Logo Search packages:      
Sourcecode: eog version File versions

eog-scroll-view.c

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <math.h>
#include <gdk-pixbuf/gdk-pixbuf.h>
#include <gdk/gdkkeysyms.h>

#include "libeog-marshal.h"
#include "eog-scroll-view.h"
#include "cursors.h"
#include "uta.h"
#include "zoom.h"

/* Maximum size of delayed repaint rectangles */
#define PAINT_RECT_WIDTH 128
#define PAINT_RECT_HEIGHT 128

/* Scroll step increment */
#define SCROLL_STEP_SIZE 32

/* Maximum zoom factor */
#define MAX_ZOOM_FACTOR 20
#define MIN_ZOOM_FACTOR 0.02

#define CHECK_MEDIUM 8
#define CHECK_BLACK 0x00000000
#define CHECK_DARK 0x00555555
#define CHECK_GRAY 0x00808080
#define CHECK_LIGHT 0x00cccccc
#define CHECK_WHITE 0x00ffffff

/* Default increment for zooming.  The current zoom factor is multiplied or
 * divided by this amount on every zooming step.  For consistency, you should
 * use the same value elsewhere in the program.
 */
#define IMAGE_VIEW_ZOOM_MULTIPLIER 1.05

#define NO_DEBUG

/* States for automatically adjusting the zoom factor */
typedef enum {
      ZOOM_MODE_FIT,          /* Image is fitted to scroll view even if the latter changes size */
      ZOOM_MODE_FREE          /* The image remains at its current zoom factor even if the scrollview changes size  */
} ZoomMode;

/* Progressive loading state */
typedef enum {
      PROGRESSIVE_NONE, /* We are not loading an image or it is already loaded */
      PROGRESSIVE_LOADING,    /* An image is being loaded */
      PROGRESSIVE_POLISHING   /* We have finished loading an image but have not scaled it with interpolation */
} ProgressiveState;

/* Signal IDs */
enum {
      SIGNAL_ZOOM_CHANGED,
      SIGNAL_LAST
};
static gint view_signals [SIGNAL_LAST];

/* Private part of the EogScrollView structure */
struct _EogScrollViewPrivate {
      /* some widgets we rely on */
      GtkWidget *display;
      GtkAdjustment *hadj;
      GtkAdjustment *vadj;
      GtkWidget *hbar;
      GtkWidget *vbar;

      /* actual image */
      EogImage *image;
      guint image_changed_id;
      GdkPixbuf *pixbuf;

      /* zoom mode, either ZOOM_MODE_FIT or ZOOM_MODE_FREE */
      ZoomMode zoom_mode;

      /* whether to allow zoom > 1.0 on zoom fit */
      gboolean upscale;

      /* the actual zoom factor */
      double zoom;

      /* the minimum possible (reasonable) zoom factor */
      double min_zoom;

      /* Current scrolling offsets */
      int xofs, yofs;

      /* Microtile arrays for dirty region.  This represents the dirty region
       * for interpolated drawing.
       */
      ArtUta *uta;

      /* handler ID for paint idle callback */
      guint idle_id;

      /* Interpolation type */
      GdkInterpType interp_type;

      /* dragging stuff */
      int drag_anchor_x, drag_anchor_y;
      int drag_ofs_x, drag_ofs_y;
      guint dragging : 1;

      /* status of progressive loading */
      ProgressiveState progressive_state;

      /* how to indicate transparency in images */
      TransparencyStyle transp_style;
      guint32 transp_color;

      /* the type of the cursor we are currently showing */
      CursorType cursor_type;
};

static void scroll_by (EogScrollView *view, int xofs, int yofs);
static void set_zoom_fit (EogScrollView *view);
static void request_paint_area (EogScrollView *view, GdkRectangle *area);
static void set_minimum_zoom_factor (EogScrollView *view);

G_DEFINE_TYPE (EogScrollView, eog_scroll_view, GTK_TYPE_TABLE)


/*===================================
    widget size changing handler &
        util functions
  ---------------------------------*/

/* Disconnects from the EogImage and removes references to it */
static void
free_image_resources (EogScrollView *view)
{
      EogScrollViewPrivate *priv;

      priv = view->priv;

      if (priv->image_changed_id > 0) {
            g_signal_handler_disconnect (G_OBJECT (priv->image), priv->image_changed_id);
            priv->image_changed_id = 0;
      }

      if (priv->image != NULL) {
            eog_image_data_unref (priv->image);
            priv->image = NULL;
      }

      if (priv->pixbuf != NULL) {
            g_object_unref (priv->pixbuf);
            priv->pixbuf = NULL;
      }
}

/* Computes the size in pixels of the scaled image */
static void
compute_scaled_size (EogScrollView *view, double zoom, int *width, int *height)
{
      EogScrollViewPrivate *priv;

      priv = view->priv;

      if (priv->pixbuf) {
            *width = floor (gdk_pixbuf_get_width (priv->pixbuf) * zoom + 0.5);
            *height = floor (gdk_pixbuf_get_height (priv->pixbuf) * zoom + 0.5);
      } else
            *width = *height = 0;
}

/* Computes the offsets for the new zoom value so that they keep the image
 * centered on the view.
 */
static void
compute_center_zoom_offsets (EogScrollView *view,
                       double old_zoom, double new_zoom,
                       int width, int height,
                       double zoom_x_anchor, double zoom_y_anchor,
                       int *xofs, int *yofs)
{
      EogScrollViewPrivate *priv;
      int old_scaled_width, old_scaled_height;
      int new_scaled_width, new_scaled_height;
      double view_cx, view_cy;

      priv = view->priv;

      compute_scaled_size (view, old_zoom,
                       &old_scaled_width, &old_scaled_height);

      if (old_scaled_width < width)
            view_cx = (zoom_x_anchor * old_scaled_width) / old_zoom;
      else
            view_cx = (priv->xofs + zoom_x_anchor * width) / old_zoom;

      if (old_scaled_height < height)
            view_cy = (zoom_y_anchor * old_scaled_height) / old_zoom;
      else
            view_cy = (priv->yofs + zoom_y_anchor * height) / old_zoom;

      compute_scaled_size (view, new_zoom,
                       &new_scaled_width, &new_scaled_height);

      if (new_scaled_width < width)
            *xofs = 0;
      else {
            *xofs = floor (view_cx * new_zoom - zoom_x_anchor * width + 0.5);
            if (*xofs < 0)
                  *xofs = 0;
      }

      if (new_scaled_height < height)
            *yofs = 0;
      else {
            *yofs = floor (view_cy * new_zoom - zoom_y_anchor * height + 0.5);
            if (*yofs < 0)
                  *yofs = 0;
      }
}

/* Sets the scrollbar values based on the current scrolling offset */
static void
update_scrollbar_values (EogScrollView *view)
{
      EogScrollViewPrivate *priv;
      int scaled_width, scaled_height;
      int xofs, yofs;
      GtkAllocation *allocation;

      priv = view->priv;

      if (!GTK_WIDGET_VISIBLE (GTK_WIDGET (priv->hbar)) && !GTK_WIDGET_VISIBLE (GTK_WIDGET (priv->vbar)))
            return;

      compute_scaled_size (view, priv->zoom, &scaled_width, &scaled_height);
      allocation = &GTK_WIDGET (priv->display)->allocation;

      if (GTK_WIDGET_VISIBLE (GTK_WIDGET (priv->hbar))) {
            /* Set scroll increments */
            priv->hadj->page_size = MIN (scaled_width, allocation->width);
            priv->hadj->page_increment = allocation->width / 2;
            priv->hadj->step_increment = SCROLL_STEP_SIZE;

            /* Set scroll bounds and new offsets */
            priv->hadj->lower = 0;
            priv->hadj->upper = scaled_width;
            xofs = CLAMP (priv->xofs, 0, priv->hadj->upper - priv->hadj->page_size);
            if (priv->hadj->value != xofs) {
                  priv->hadj->value = xofs;
                  priv->xofs = xofs;

                  g_signal_handlers_block_matched (
                        priv->hadj, G_SIGNAL_MATCH_DATA,
                        0, 0, NULL, NULL, view);

                  gtk_adjustment_changed (priv->hadj);

                  g_signal_handlers_unblock_matched (
                        priv->hadj, G_SIGNAL_MATCH_DATA,
                        0, 0, NULL, NULL, view);
            }
      }

      if (GTK_WIDGET_VISIBLE (GTK_WIDGET (priv->vbar))) {
            priv->vadj->page_size = MIN (scaled_height, allocation->height);
            priv->vadj->page_increment = allocation->height / 2;
            priv->vadj->step_increment = SCROLL_STEP_SIZE;

            priv->vadj->lower = 0;
            priv->vadj->upper = scaled_height;
            yofs = CLAMP (priv->yofs, 0, priv->vadj->upper - priv->vadj->page_size);

            if (priv->vadj->value != yofs) {
                  priv->vadj->value = yofs;
                  priv->yofs = yofs;

                  g_signal_handlers_block_matched (
                        priv->vadj, G_SIGNAL_MATCH_DATA,
                        0, 0, NULL, NULL, view);

                  gtk_adjustment_changed (priv->vadj);

                  g_signal_handlers_unblock_matched (
                        priv->vadj, G_SIGNAL_MATCH_DATA,
                        0, 0, NULL, NULL, view);
            }
      }
}

/* Changes visibility of the scrollbars based on the zoom factor and the
 * specified allocation, or the current allocation if NULL is specified.
 */
static void
check_scrollbar_visibility (EogScrollView *view, GtkAllocation *alloc)
{
      EogScrollViewPrivate *priv;
      int bar_height;
      int bar_width;
      int img_width;
      int img_height;
      GtkRequisition req;
      int width, height;
      gboolean hbar_visible, vbar_visible;

      priv = view->priv;

      if (alloc) {
            width = alloc->width;
            height = alloc->height;
      } else {
            width = GTK_WIDGET (view)->allocation.width;
            height = GTK_WIDGET (view)->allocation.height;
      }

      compute_scaled_size (view, priv->zoom, &img_width, &img_height);

      /* this should work fairly well in this special case for scrollbars */
      gtk_widget_size_request (priv->hbar, &req);
      bar_height = req.height;
      gtk_widget_size_request (priv->vbar, &req);
      bar_width = req.width;

#ifdef DEBUG
      g_print ("Widget Size allocate: %i, %i   bar: %i, %i\n", width, height, bar_width, bar_height);
#endif

      hbar_visible = vbar_visible = FALSE;
      if (priv->zoom_mode == ZOOM_MODE_FIT)
            hbar_visible = vbar_visible = FALSE;
      else if (img_width <= width && img_height <= height)
            hbar_visible = vbar_visible = FALSE;
      else if (img_width > width && img_height > height)
            hbar_visible = vbar_visible = TRUE;
      else if (img_width > width) {
            hbar_visible = TRUE;
            if (img_height <= (height - bar_height))
                  vbar_visible = FALSE;
            else
                  vbar_visible = TRUE;
      }
        else if (img_height > height) {
            vbar_visible = TRUE;
            if (img_width <= (width - bar_width))
                  hbar_visible = FALSE;
            else
                  hbar_visible = TRUE;
      }

      if (hbar_visible != GTK_WIDGET_VISIBLE (GTK_WIDGET (priv->hbar)))
            g_object_set (G_OBJECT (priv->hbar), "visible", hbar_visible, NULL);

      if (vbar_visible != GTK_WIDGET_VISIBLE (GTK_WIDGET (priv->vbar)))
            g_object_set (G_OBJECT (priv->vbar), "visible", vbar_visible, NULL);


      if ((hbar_visible || vbar_visible) && priv->cursor_type != CURSOR_HAND_OPEN) {
            priv->cursor_type = CURSOR_HAND_OPEN;
            cursor_set (priv->display, CURSOR_HAND_OPEN);
      }
      else if (!hbar_visible  && !vbar_visible && priv->cursor_type != CURSOR_DEFAULT) {
            priv->cursor_type = CURSOR_DEFAULT;
            cursor_set (priv->display, CURSOR_DEFAULT);
      }
}

#define DOUBLE_EQUAL_MAX_DIFF 1e-6
#define DOUBLE_EQUAL(a,b) (fabs (a - b) < DOUBLE_EQUAL_MAX_DIFF)

/* Returns whether the zoom factor is 1.0 */
static gboolean
is_unity_zoom (EogScrollView *view)
{
      EogScrollViewPrivate *priv;

      priv = view->priv;
      return DOUBLE_EQUAL (priv->zoom, 1.0);
}

/* Returns wether the image is movable, that means if it is larger then 
 * the actual visible area.
 */
static gboolean
is_image_movable (EogScrollView *view)
{
      EogScrollViewPrivate *priv;

      priv = view->priv;

      return (GTK_WIDGET_VISIBLE (priv->hbar) || GTK_WIDGET_VISIBLE (priv->vbar));
}


/* Computes the image offsets with respect to the window */
/*
static void
get_image_offsets (EogScrollView *view, int *xofs, int *yofs)
{
      EogScrollViewPrivate *priv;
      int scaled_width, scaled_height;
      int width, height;

      priv = view->priv;

      compute_scaled_size (view, priv->zoom, &scaled_width, &scaled_height);

      width = GTK_WIDGET (priv->display)->allocation.width;
      height = GTK_WIDGET (priv->display)->allocation.height;

      // Compute image offsets with respect to the window
      if (scaled_width <= width)
            *xofs = (width - scaled_width) / 2;
      else
            *xofs = -priv->xofs;

      if (scaled_height <= height)
            *yofs = (height - scaled_height) / 2;
      else
            *yofs = -priv->yofs;
}
*/

/*===================================
          drawing core
  ---------------------------------*/


/* Pulls a rectangle from the specified microtile array.  The rectangle is the
 * first one that would be glommed together by art_rect_list_from_uta(), and its
 * size is bounded by max_width and max_height.  The rectangle is also removed
 * from the microtile array.
 */
static void
pull_rectangle (ArtUta *uta, ArtIRect *rect, int max_width, int max_height)
{
      uta_find_first_glom_rect (uta, rect, max_width, max_height);
      uta_remove_rect (uta, rect->x0, rect->y0, rect->x1, rect->y1);
}

/* Paints a rectangle with the background color if the specified rectangle
 * intersects the dirty rectangle.
 */
static void
paint_background (EogScrollView *view, ArtIRect *r, ArtIRect *rect)
{
      EogScrollViewPrivate *priv;
      ArtIRect d;

      priv = view->priv;

      art_irect_intersect (&d, r, rect);
      if (!art_irect_empty (&d)) {
            gdk_window_clear_area (GTK_WIDGET (priv->display)->window,
                               d.x0, d.y0,
                               d.x1 - d.x0, d.y1 - d.y0);
      }
}

/* Paints a rectangle of the dirty region */
static void
paint_rectangle (EogScrollView *view, ArtIRect *rect, GdkInterpType interp_type)
{
      EogScrollViewPrivate *priv;
      int scaled_width, scaled_height;
      int width, height;
      int xofs, yofs;
      ArtIRect r, d;
      GdkPixbuf *tmp;
      int check_size;
      guint32 check_1 = 0;
      guint32 check_2 = 0;

      priv = view->priv;

      if (!GTK_WIDGET_DRAWABLE (priv->display))
            return;

      compute_scaled_size (view, priv->zoom, &scaled_width, &scaled_height);

      width = GTK_WIDGET (priv->display)->allocation.width;
      height = GTK_WIDGET (priv->display)->allocation.height;

      if (scaled_width < 1 || scaled_height < 1)
      {
            r.x0 = 0;
            r.y0 = 0;
            r.x1 = width;
            r.y1 = height;
            paint_background (view, &r, rect);
            return;
      }
      
      /* Compute image offsets with respect to the window */

      if (scaled_width <= width)
            xofs = (width - scaled_width) / 2;
      else
            xofs = -priv->xofs;

      if (scaled_height <= height)
            yofs = (height - scaled_height) / 2;
      else
            yofs = -priv->yofs;

#ifdef DEBUG
      g_print ("paint_rectangle: zoom %.2f, xofs: %i, yofs: %i scaled w: %i h: %i\n", priv->zoom, xofs, yofs, scaled_width, scaled_height);
#endif
      /* Draw background if necessary, in four steps */

      /* Top */
      if (yofs > 0) {
            r.x0 = 0;
            r.y0 = 0;
            r.x1 = width;
            r.y1 = yofs;
            paint_background (view, &r, rect);
      }

      /* Left */
      if (xofs > 0) {
            r.x0 = 0;
            r.y0 = yofs;
            r.x1 = xofs;
            r.y1 = yofs + scaled_height;
            paint_background (view, &r, rect);
      }

      /* Right */
      if (xofs >= 0) {
            r.x0 = xofs + scaled_width;
            r.y0 = yofs;
            r.x1 = width;
            r.y1 = yofs + scaled_height;
            if (r.x0 < r.x1)
                  paint_background (view, &r, rect);
      }

      /* Bottom */
      if (yofs >= 0) {
            r.x0 = 0;
            r.y0 = yofs + scaled_height;
            r.x1 = width;
            r.y1 = height;
            if (r.y0 < r.y1)
                  paint_background (view, &r, rect);
      }


      /* Draw the scaled image
       *
       * FIXME: this is not using the color correction tables!
       */

      if (!priv->pixbuf)
            return;

      r.x0 = xofs;
      r.y0 = yofs;
      r.x1 = xofs + scaled_width;
      r.y1 = yofs + scaled_height;

      art_irect_intersect (&d, &r, rect);
      if (art_irect_empty (&d))
            return;

#ifdef R_DEBUG
 {
       char *str;
       switch (interp_type) {
       case GDK_INTERP_NEAREST:
             str = "NEAREST";
             break;
       default:
             str = "ALIASED";
       }
      g_print ("%s: x0: %i,\t y0: %i,\t x1: %i,\t y1: %i\n", str, d.x0, d.y0, d.x1, d.y1);
 }
#endif

      /* Short-circuit the fast case to avoid a memcpy() */

      if (is_unity_zoom (view)
          && gdk_pixbuf_get_colorspace (priv->pixbuf) == GDK_COLORSPACE_RGB
          && !gdk_pixbuf_get_has_alpha (priv->pixbuf)
          && gdk_pixbuf_get_bits_per_sample (priv->pixbuf) == 8) {
            guchar *pixels;
            int rowstride;

            rowstride = gdk_pixbuf_get_rowstride (priv->pixbuf);

            pixels = (gdk_pixbuf_get_pixels (priv->pixbuf)
                    + (d.y0 - yofs) * rowstride
                    + 3 * (d.x0 - xofs));

            gdk_draw_rgb_image_dithalign (GTK_WIDGET (priv->display)->window,
                                    GTK_WIDGET (priv->display)->style->black_gc,
                                    d.x0, d.y0,
                                    d.x1 - d.x0, d.y1 - d.y0,
                                    GDK_RGB_DITHER_MAX,
                                    pixels,
                                    rowstride,
                                    d.x0 - xofs, d.y0 - yofs);
            return;
      }

      /* For all other cases, create a temporary pixbuf */

      tmp = gdk_pixbuf_new (GDK_COLORSPACE_RGB, FALSE, 8, d.x1 - d.x0, d.y1 - d.y0);

      if (!tmp) {
            g_message ("paint_rectangle(): Could not allocate temporary pixbuf of "
                     "size (%d, %d); skipping", d.x1 - d.x0, d.y1 - d.y0);
            return;
      }

      /* Compute transparency parameters */
      switch (priv->transp_style) {
      case TRANSP_BACKGROUND: {
            GdkColor color = GTK_WIDGET (priv->display)->style->bg[GTK_STATE_NORMAL];

            check_1 = check_2 = (((color.red & 0xff00) << 8)
                             | (color.green & 0xff00)
                             | ((color.blue & 0xff00) >> 8));
            break; }

      case TRANSP_CHECKED:
            check_1 = CHECK_GRAY;
            check_2 = CHECK_LIGHT;
            break;

      case TRANSP_COLOR:
            check_1 = check_2 = priv->transp_color;
            break;

      default:
            g_assert_not_reached ();
      };

      check_size = CHECK_MEDIUM;

      /* Draw! */
      gdk_pixbuf_composite_color (priv->pixbuf,
                            tmp,
                            0, 0,
                            d.x1 - d.x0, d.y1 - d.y0,
                            -(d.x0 - xofs), -(d.y0 - yofs),
                            priv->zoom, priv->zoom,
                            is_unity_zoom (view) ? GDK_INTERP_NEAREST : interp_type,
                            255,
                            d.x0 - xofs, d.y0 - yofs,
                            check_size,
                            check_1, check_2);

      gdk_draw_rgb_image_dithalign (GTK_WIDGET (priv->display)->window,
                              GTK_WIDGET (priv->display)->style->black_gc,
                              d.x0, d.y0,
                              d.x1 - d.x0, d.y1 - d.y0,
                              GDK_RGB_DITHER_MAX,
                              gdk_pixbuf_get_pixels (tmp),
                              gdk_pixbuf_get_rowstride (tmp),
                              d.x0 - xofs, d.y0 - yofs);

      g_object_unref (tmp);
}


/* Idle handler for the drawing process.  We pull a rectangle from the dirty
 * region microtile array, paint it, and leave the rest to the next idle
 * iteration.
 */
static gboolean
paint_iteration_idle (gpointer data)
{
      EogScrollView *view;
      EogScrollViewPrivate *priv;
      ArtIRect rect;

      view = EOG_SCROLL_VIEW (data);
      priv = view->priv;

      g_assert (priv->uta != NULL);

      pull_rectangle (priv->uta, &rect, PAINT_RECT_WIDTH, PAINT_RECT_HEIGHT);

      if (art_irect_empty (&rect)) {
            art_uta_free (priv->uta);
            priv->uta = NULL;
      } else
            paint_rectangle (view, &rect, priv->interp_type);

      if (!priv->uta) {
            priv->idle_id = 0;
            return FALSE;
      }

      return TRUE;
}

/* Paints the requested area in non-interpolated mode.  Then, if we are
 * configured to use interpolation, we queue an idle handler to redraw the area
 * with interpolation.  The area is in window coordinates.
 */
static void
request_paint_area (EogScrollView *view, GdkRectangle *area)
{
      EogScrollViewPrivate *priv;
      ArtIRect r;

      priv = view->priv;

#ifdef R_DEBUG
      g_print ("request_paint area: ...  x: %i, y: %i, width: %i, height: %i\n", area->x, area->y, area->width, area->height);
#endif

      if (!GTK_WIDGET_DRAWABLE (priv->display))
            return;

      r.x0 = MAX (0, area->x);
      r.y0 = MAX (0, area->y);
      r.x1 = MIN (GTK_WIDGET (priv->display)->allocation.width, area->x + area->width);
      r.y1 = MIN (GTK_WIDGET (priv->display)->allocation.height, area->y + area->height);

#ifdef DEBUG
      g_print ("request_paint r: %i, %i, %i, %i\n", r.x0, r.y0, r.x1, r.y1);
#endif

      if (r.x0 >= r.x1 || r.y0 >= r.y1)
            return;

      /* Do nearest neighbor, 1:1 zoom or active progressive loading synchronously for speed.  */
      if (priv->interp_type == GDK_INTERP_NEAREST ||
          is_unity_zoom (view) ||
          priv->progressive_state == PROGRESSIVE_LOADING) {
            paint_rectangle (view, &r, GDK_INTERP_NEAREST);
            return;
      }

      if (priv->progressive_state == PROGRESSIVE_POLISHING)
            /* We have already a complete image with nearest neighbor mode.
             * It's sufficient to add only a antitaliased idle update
             */
            priv->progressive_state = PROGRESSIVE_NONE;
      else
            /* do nearest neigbor before anti aliased version */
            paint_rectangle (view, &r, GDK_INTERP_NEAREST);

      /* All other interpolation types are delayed.  */
      if (priv->uta)
            g_assert (priv->idle_id != 0);
      else {
            g_assert (priv->idle_id == 0);
            priv->idle_id = g_idle_add (paint_iteration_idle, view);
      }

      priv->uta = uta_add_rect (priv->uta, r.x0, r.y0, r.x1, r.y1);
}


/* =======================================

    scrolling stuff

    --------------------------------------*/


/* Scrolls the view to the specified offsets.  */
static void
scroll_to (EogScrollView *view, int x, int y, gboolean change_adjustments)
{
      EogScrollViewPrivate *priv;
      int xofs, yofs;
      GdkWindow *window;
      int width, height;
      int src_x, src_y;
      int dest_x, dest_y;
      int twidth, theight;

      priv = view->priv;

      /* Check bounds & Compute offsets */
      if (GTK_WIDGET_VISIBLE (priv->hbar)) {
            x = CLAMP (x, 0, priv->hadj->upper - priv->hadj->page_size);
            xofs = x - priv->xofs;
      } else
            xofs = 0;

      if (GTK_WIDGET_VISIBLE (priv->vbar)) {
            y = CLAMP (y, 0, priv->vadj->upper - priv->vadj->page_size);
            yofs = y - priv->yofs;
      } else
            yofs = 0;

      if (xofs == 0 && yofs == 0)
            return;

      priv->xofs = x;
      priv->yofs = y;

      if (!GTK_WIDGET_DRAWABLE (priv->display))
            goto out;

      width = GTK_WIDGET (priv->display)->allocation.width;
      height = GTK_WIDGET (priv->display)->allocation.height;

      if (abs (xofs) >= width || abs (yofs) >= height) {
            gtk_widget_queue_draw (GTK_WIDGET (priv->display));
            goto out;
      }

      window = GTK_WIDGET (priv->display)->window;

      /* Ensure that the uta has the full size */

      twidth = (width + ART_UTILE_SIZE - 1) >> ART_UTILE_SHIFT;
      theight = (height + ART_UTILE_SIZE - 1) >> ART_UTILE_SHIFT;

      if (priv->uta)
            g_assert (priv->idle_id != 0);
      else
            priv->idle_id = g_idle_add (paint_iteration_idle, view);

      priv->uta = uta_ensure_size (priv->uta, 0, 0, twidth, theight);

      /* Copy the uta area.  Our synchronous handling of expose events, below,
       * will queue the new scrolled-in areas.
       */
      src_x = xofs < 0 ? 0 : xofs;
      src_y = yofs < 0 ? 0 : yofs;
      dest_x = xofs < 0 ? -xofs : 0;
      dest_y = yofs < 0 ? -yofs : 0;

      uta_copy_area (priv->uta,
                   src_x, src_y,
                   dest_x, dest_y,
                   width - abs (xofs), height - abs (yofs));

      /* Scroll the window area and process exposure synchronously. */

      gdk_window_scroll (window, -xofs, -yofs);
      gdk_window_process_updates (window, TRUE);

 out:
      if (!change_adjustments)
            return;

      g_signal_handlers_block_matched (
            priv->hadj, G_SIGNAL_MATCH_DATA,
            0, 0, NULL, NULL, view);
      g_signal_handlers_block_matched (
            priv->vadj, G_SIGNAL_MATCH_DATA,
            0, 0, NULL, NULL, view);

      priv->hadj->value = x;
      priv->vadj->value = y;

      gtk_adjustment_value_changed (priv->hadj);
      gtk_adjustment_value_changed (priv->vadj);

      g_signal_handlers_unblock_matched (
            priv->hadj, G_SIGNAL_MATCH_DATA,
            0, 0, NULL, NULL, view);
      g_signal_handlers_unblock_matched (
            priv->vadj, G_SIGNAL_MATCH_DATA,
            0, 0, NULL, NULL, view);
}

/* Scrolls the image view by the specified offsets.  Notifies the adjustments
 * about their new values.
 */
static void
scroll_by (EogScrollView *view, int xofs, int yofs)
{
      EogScrollViewPrivate *priv;

      priv = view->priv;

      scroll_to (view, priv->xofs + xofs, priv->yofs + yofs, TRUE);
}


/* Callback used when an adjustment is changed */
static void
adjustment_changed_cb (GtkAdjustment *adj, gpointer data)
{
      EogScrollView *view;
      EogScrollViewPrivate *priv;

      view = EOG_SCROLL_VIEW (data);
      priv = view->priv;

      scroll_to (view, priv->hadj->value, priv->vadj->value, FALSE);
}


/* Drags the image to the specified position */
static void
drag_to (EogScrollView *view, int x, int y)
{
      EogScrollViewPrivate *priv;
      int dx, dy;

      priv = view->priv;

      dx = priv->drag_anchor_x - x;
      dy = priv->drag_anchor_y - y;

      x = priv->drag_ofs_x + dx;
      y = priv->drag_ofs_y + dy;

      scroll_to (view, x, y, TRUE);
}

static void
set_minimum_zoom_factor (EogScrollView *view)
{
      g_return_if_fail (EOG_IS_SCROLL_VIEW (view));
      
      view->priv->min_zoom = MAX (1.0 / gdk_pixbuf_get_width (view->priv->pixbuf),
                            MAX(1.0 / gdk_pixbuf_get_height (view->priv->pixbuf),
                              MIN_ZOOM_FACTOR) );
      return;
}

/**
 * set_zoom:
 * @view: A scroll view.
 * @zoom: Zoom factor.
 * @have_anchor: Whether the anchor point specified by (@anchorx, @anchory)
 * should be used.
 * @anchorx: Horizontal anchor point in pixels.
 * @anchory: Vertical anchor point in pixels.
 *
 * Sets the zoom factor for an image view.  The anchor point can be used to
 * specify the point that stays fixed when the image is zoomed.  If @have_anchor
 * is %TRUE, then (@anchorx, @anchory) specify the point relative to the image
 * view widget's allocation that will stay fixed when zooming.  If @have_anchor
 * is %FALSE, then the center point of the image view will be used.
 **/
static void
set_zoom (EogScrollView *view, double zoom,
        gboolean have_anchor, int anchorx, int anchory)
{
      EogScrollViewPrivate *priv;
      int xofs, yofs;
      int disp_width, disp_height;
      double x_rel, y_rel;

      g_assert (zoom > 0.0);

      priv = view->priv;

      if (priv->pixbuf == NULL)
            return;

      if (zoom > MAX_ZOOM_FACTOR)
            zoom = MAX_ZOOM_FACTOR;
      else if (zoom < MIN_ZOOM_FACTOR)
            zoom = MIN_ZOOM_FACTOR;

      if (DOUBLE_EQUAL (priv->zoom, zoom))
            return;
      if (DOUBLE_EQUAL (priv->zoom, priv->min_zoom) && zoom < priv->zoom)
            return;

      priv->zoom_mode = ZOOM_MODE_FREE;

      disp_width = GTK_WIDGET (priv->display)->allocation.width;
      disp_height = GTK_WIDGET (priv->display)->allocation.height;

      /* compute new xofs/yofs values */
      if (have_anchor) {
            x_rel = (double) anchorx / disp_width;
            y_rel = (double) anchory / disp_height;
      } else {
            x_rel = 0.5;
            y_rel = 0.5;
      }

      compute_center_zoom_offsets (view, priv->zoom, zoom,
                             disp_width, disp_height,
                             x_rel, y_rel,
                             &xofs, &yofs);

      /* set new values */
      priv->xofs = xofs; /* (img_width * x_rel * zoom) - anchorx; */
      priv->yofs = yofs; /* (img_height * y_rel * zoom) - anchory; */
#if 0
      g_print ("xofs: %i  yofs: %i\n", priv->xofs, priv->yofs);
#endif
      if (zoom <= priv->min_zoom)
            priv->zoom = priv->min_zoom;
      else
            priv->zoom = zoom;

      /* we make use of the new values here */
      check_scrollbar_visibility (view, NULL);
      update_scrollbar_values (view);

      /* repaint the whole image */
      gtk_widget_queue_draw (GTK_WIDGET (priv->display));

      g_signal_emit (view, view_signals [SIGNAL_ZOOM_CHANGED], 0, priv->zoom);
}

/* Zooms the image to fit the available allocation */
static void
set_zoom_fit (EogScrollView *view)
{
      EogScrollViewPrivate *priv;
      double new_zoom;
      int width, height;

      priv = view->priv;

      priv->zoom_mode = ZOOM_MODE_FIT;

      if (!GTK_WIDGET_MAPPED (GTK_WIDGET (view)))
            return;

      if (priv->pixbuf == NULL)
            return;

      width = GTK_WIDGET (priv->display)->allocation.width;
      height = GTK_WIDGET (priv->display)->allocation.height;

      new_zoom = zoom_fit_scale (width, height,
                           gdk_pixbuf_get_width (priv->pixbuf),
                           gdk_pixbuf_get_height (priv->pixbuf),
                           priv->upscale);

      if (new_zoom > MAX_ZOOM_FACTOR)
            new_zoom = MAX_ZOOM_FACTOR;
      else if (new_zoom < MIN_ZOOM_FACTOR)
            new_zoom = MIN_ZOOM_FACTOR;

      priv->zoom = new_zoom;
      priv->xofs = 0;
      priv->yofs = 0;

      g_signal_emit (view, view_signals [SIGNAL_ZOOM_CHANGED], 0, priv->zoom);
}

/*===================================

   internal signal callbacks

  ---------------------------------*/

/* Key press event handler for the image view */
static gboolean
display_key_press_event (GtkWidget *widget, GdkEventKey *event, gpointer data)
{
      EogScrollView *view;
      EogScrollViewPrivate *priv;
      gboolean do_zoom;
      double zoom;
      gboolean do_scroll;
      int xofs, yofs;
      int width, height;

      view = EOG_SCROLL_VIEW (data);
      priv = view->priv;

      do_zoom = FALSE;
      do_scroll = FALSE;
      xofs = yofs = 0;
      zoom = 1.0;

      width = GTK_WIDGET (priv->display)->allocation.width;
      height = GTK_WIDGET (priv->display)->allocation.height;

      switch (event->keyval) {
      case GDK_Up:
            do_scroll = TRUE;
            xofs = 0;
            yofs = -SCROLL_STEP_SIZE;
            break;

      case GDK_Page_Up:
            do_scroll = TRUE;
            if (event->state & GDK_CONTROL_MASK) {
                  xofs = -(width * 3) / 4;
                  yofs = 0;
            } else {
                  xofs = 0;
                  yofs = -(height * 3) / 4;
            }
            break;

      case GDK_Down:
            do_scroll = TRUE;
            xofs = 0;
            yofs = SCROLL_STEP_SIZE;
            break;

      case GDK_Page_Down:
            do_scroll = TRUE;
            if (event->state & GDK_CONTROL_MASK) {
                  xofs = (width * 3) / 4;
                  yofs = 0;
            } else {
                  xofs = 0;
                  yofs = (height * 3) / 4;
            }
            break;

      case GDK_Left:
            do_scroll = TRUE;
            xofs = -SCROLL_STEP_SIZE;
            yofs = 0;
            break;

      case GDK_Right:
            do_scroll = TRUE;
            xofs = SCROLL_STEP_SIZE;
            yofs = 0;
            break;

      case GDK_plus:
      case GDK_equal:
      case GDK_KP_Add:
            do_zoom = TRUE;
            zoom = priv->zoom * IMAGE_VIEW_ZOOM_MULTIPLIER;
            break;

      case GDK_minus:
      case GDK_KP_Subtract:
            do_zoom = TRUE;
            zoom = priv->zoom / IMAGE_VIEW_ZOOM_MULTIPLIER;
            break;

      case GDK_1:
            do_zoom = TRUE;
            zoom = 1.0;
            break;

      case GDK_F:
      case GDK_f:
            set_zoom_fit (view);
            check_scrollbar_visibility (view, NULL);
            gtk_widget_queue_draw (GTK_WIDGET (priv->display));
            break;

      default:
            return FALSE;
      }

      if (do_zoom) {
            gint x, y;

            gdk_window_get_pointer (widget->window, &x, &y, NULL);
            set_zoom (view, zoom, TRUE, x, y);
      }

      if (do_scroll)
            scroll_by (view, xofs, yofs);

      return TRUE;
}


/* Button press event handler for the image view */
static gboolean
eog_scroll_view_button_press_event (GtkWidget *widget, GdkEventButton *event, gpointer data)
{
      EogScrollView *view;
      EogScrollViewPrivate *priv;

      view = EOG_SCROLL_VIEW (data);
      priv = view->priv;

      if (!GTK_WIDGET_HAS_FOCUS (priv->display))
            gtk_widget_grab_focus (GTK_WIDGET (priv->display));

      if (priv->dragging)
            return FALSE;

      switch (event->button) {
            case 1:
            case 2:
                  if (is_image_movable (view)) {
                        priv->cursor_type = CURSOR_HAND_CLOSED;
                        cursor_set (GTK_WIDGET (priv->display), CURSOR_HAND_CLOSED);

                        priv->dragging = TRUE;
                        priv->drag_anchor_x = event->x;
                        priv->drag_anchor_y = event->y;

                        priv->drag_ofs_x = priv->xofs;
                        priv->drag_ofs_y = priv->yofs;

                        return TRUE;
                  }
            default:
                  break;
      }

      return FALSE;
}

static void
eog_scroll_view_style_set (GtkWidget *widget, GtkStyle *old_style)
{
      GtkStyle *style;
      EogScrollViewPrivate *priv;

      style = gtk_widget_get_style (widget);
      priv = EOG_SCROLL_VIEW (widget)->priv;

      gtk_widget_set_style (priv->display, style);
}


/* Button release event handler for the image view */
static gboolean
eog_scroll_view_button_release_event (GtkWidget *widget, GdkEventButton *event, gpointer data)
{
      EogScrollView *view;
      EogScrollViewPrivate *priv;

      view = EOG_SCROLL_VIEW (data);
      priv = view->priv;

      if (!priv->dragging)
            return FALSE;

      switch (event->button) {
            case 1:
            case 2:
                  drag_to (view, event->x, event->y);
                  priv->dragging = FALSE;

                  if (is_image_movable (view)) {
                        priv->cursor_type = CURSOR_HAND_OPEN;
                        cursor_set (GTK_WIDGET (priv->display), CURSOR_HAND_OPEN);
                  }
                  else {
                        priv->cursor_type = CURSOR_DEFAULT;
                        cursor_set (GTK_WIDGET (priv->display), CURSOR_DEFAULT);
                  }

            default:
                  break;
      }

      return TRUE;
}

/* Scroll event handler for the image view.  We zoom with an event without
 * modifiers rather than scroll; we use the Shift modifier to scroll.
 * Rationale: images are not primarily vertical, and in EOG you scan scroll by
 * dragging the image with button 1 anyways.
 */
static gboolean
eog_scroll_view_scroll_event (GtkWidget *widget, GdkEventScroll *event, gpointer data)
{
      EogScrollView *view;
      EogScrollViewPrivate *priv;
      double zoom_factor;
      int xofs, yofs;

      view = EOG_SCROLL_VIEW (data);
      priv = view->priv;

      /* Compute zoom factor and scrolling offsets; we'll only use either of them */

      xofs = priv->hadj->page_increment / 2; /* same as in gtkscrolledwindow.c */
      yofs = priv->vadj->page_increment / 2;

      switch (event->direction) {
      case GDK_SCROLL_UP:
            zoom_factor = IMAGE_VIEW_ZOOM_MULTIPLIER;
            xofs = 0;
            yofs = -yofs;
            break;

      case GDK_SCROLL_LEFT:
            zoom_factor = 1.0 / IMAGE_VIEW_ZOOM_MULTIPLIER;
            xofs = -xofs;
            yofs = 0;
            break;

      case GDK_SCROLL_DOWN:
            zoom_factor = 1.0 / IMAGE_VIEW_ZOOM_MULTIPLIER;
            xofs = 0;
            yofs = yofs;
            break;

      case GDK_SCROLL_RIGHT:
            zoom_factor = IMAGE_VIEW_ZOOM_MULTIPLIER;
            xofs = xofs;
            yofs = 0;
            break;

      default:
            g_assert_not_reached ();
            return FALSE;
      }

      if ((event->state & GDK_SHIFT_MASK) == 0)
            set_zoom (view, priv->zoom * zoom_factor,
                    TRUE, event->x, event->y);
      else if ((event->state & GDK_CONTROL_MASK) == 0)
            scroll_by (view, xofs, yofs);
      else
            scroll_by (view, yofs, xofs);

      return TRUE;
}

/* Motion event handler for the image view */
static gboolean
eog_scroll_view_motion_event (GtkWidget *widget, GdkEventMotion *event, gpointer data)
{
      EogScrollView *view;
      EogScrollViewPrivate *priv;
      gint x, y;
      GdkModifierType mods;

      view = EOG_SCROLL_VIEW (data);
      priv = view->priv;

      if (!priv->dragging)
            return FALSE;

      if (event->is_hint)
            gdk_window_get_pointer (GTK_WIDGET (priv->display)->window, &x, &y, &mods);
      else {
            x = event->x;
            y = event->y;
      }

      drag_to (view, x, y);
      return TRUE;
}

static void
display_map_event (GtkWidget *widget, GdkEvent *event, gpointer data)
{
      EogScrollView *view;
      EogScrollViewPrivate *priv;

      view = EOG_SCROLL_VIEW (data);
      priv = view->priv;

#ifdef DEBUG
      g_print ("display_map_event ...\n");
#endif

      set_zoom_fit (view);
      check_scrollbar_visibility (view, NULL);
      gtk_widget_queue_draw (GTK_WIDGET (priv->display));
}

static void
eog_scroll_view_size_allocate (GtkWidget *widget, GtkAllocation *alloc)
{
      EogScrollView *view;

      view = EOG_SCROLL_VIEW (widget);
      check_scrollbar_visibility (view, alloc);

      GTK_WIDGET_CLASS (eog_scroll_view_parent_class)->size_allocate (widget
                                                      ,alloc);
}

static void
display_size_change (GtkWidget *widget, GdkEventConfigure *event, gpointer data)
{
      EogScrollView *view;
      EogScrollViewPrivate *priv;

      view = EOG_SCROLL_VIEW (data);
      priv = view->priv;

      if (priv->zoom_mode == ZOOM_MODE_FIT) {
            GtkAllocation alloc;

            alloc.width = event->width;
            alloc.height = event->height;

            set_zoom_fit (view);
            check_scrollbar_visibility (view, &alloc);
            gtk_widget_queue_draw (GTK_WIDGET (priv->display));
      } else {
            int scaled_width, scaled_height;
            int x_offset = 0;
            int y_offset = 0;

            compute_scaled_size (view, priv->zoom, &scaled_width, &scaled_height);

            if (priv->xofs + event->width > scaled_width)
                  x_offset = scaled_width - event->width - priv->xofs;

            if (priv->yofs + event->height > scaled_height)
                  y_offset = scaled_height - event->height - priv->yofs;

            scroll_by (view, x_offset, y_offset);
      }

      update_scrollbar_values (view);
}


static gboolean
eog_scroll_view_focus_in_event (GtkWidget     *widget,
                      GdkEventFocus *event,
                      gpointer data)
{
      g_signal_stop_emission_by_name (G_OBJECT (widget), "focus_in_event");
      return FALSE;
}

static gboolean
eog_scroll_view_focus_out_event (GtkWidget     *widget,
                       GdkEventFocus *event,
                       gpointer data)
{
      g_signal_stop_emission_by_name (G_OBJECT (widget), "focus_out_event");
      return FALSE;
}

/* Expose event handler for the drawing area.  First we process the whole dirty
 * region by drawing a non-interpolated version, which is "instantaneous", and
 * we do this synchronously.  Then, if we are set to use interpolation, we queue
 * an idle handler to handle interpolated drawing there.
 */
static gboolean
display_expose_event (GtkWidget *widget, GdkEventExpose *event, gpointer data)
{
      EogScrollView *view;
      GdkRectangle *rects;
      gint n_rects;
      int i;

      g_return_val_if_fail (GTK_IS_DRAWING_AREA (widget), FALSE);
      g_return_val_if_fail (event != NULL, FALSE);
      g_return_val_if_fail (EOG_IS_SCROLL_VIEW (data), FALSE);

      view = EOG_SCROLL_VIEW (data);

      gdk_region_get_rectangles (event->region, &rects, &n_rects);

      for (i = 0; i < n_rects; i++) {
            request_paint_area (view, rects + i);
      }

      g_free (rects);

      return TRUE;
}


/*==================================

   image loading callbacks

   -----------------------------------*/
/*
static void
image_loading_update_cb (EogImage *img, int x, int y, int width, int height, gpointer data)
{
      EogScrollView *view;
      EogScrollViewPrivate *priv;
      GdkRectangle area;
      int xofs, yofs;
      int sx0, sy0, sx1, sy1;

      view = (EogScrollView*) data;
      priv = view->priv;

#ifdef DEBUG
      g_print ("image_update_cb: x: %i, y: %i, width: %i, height: %i\n", x, y, width, height);
#endif

      if (priv->pixbuf == NULL) {
            priv->pixbuf = eog_image_get_pixbuf (img);
            set_zoom_fit (view);
            check_scrollbar_visibility (view, NULL);
      }
      priv->progressive_state = PROGRESSIVE_LOADING;

      get_image_offsets (view, &xofs, &yofs);

      sx0 = floor (x * priv->zoom + xofs);
      sy0 = floor (y * priv->zoom + yofs);
      sx1 = ceil ((x + width) * priv->zoom + xofs);
      sy1 = ceil ((y + height) * priv->zoom + yofs);

      area.x = sx0;
      area.y = sy0;
      area.width = sx1 - sx0;
      area.height = sy1 - sy0;

      if (GTK_WIDGET_DRAWABLE (priv->display))
            gdk_window_invalidate_rect (GTK_WIDGET (priv->display)->window, &area, FALSE);
}


static void
image_loading_finished_cb (EogImage *img, gpointer data)
{
      EogScrollView *view;
      EogScrollViewPrivate *priv;

      view = (EogScrollView*) data;
      priv = view->priv;

      if (priv->pixbuf == NULL) {
            priv->pixbuf = eog_image_get_pixbuf (img);
            priv->progressive_state = PROGRESSIVE_NONE;
            set_zoom_fit (view);
            check_scrollbar_visibility (view, NULL);
            gtk_widget_queue_draw (GTK_WIDGET (priv->display));

      }
      else if (priv->interp_type != GDK_INTERP_NEAREST &&
             !is_unity_zoom (view))
      {
            // paint antialiased image version 
            priv->progressive_state = PROGRESSIVE_POLISHING;
            gtk_widget_queue_draw (GTK_WIDGET (priv->display));
      }
}

static void
image_loading_failed_cb (EogImage *img, char *msg, gpointer data)
{
      EogScrollViewPrivate *priv;

      priv = EOG_SCROLL_VIEW (data)->priv;

      g_print ("loading failed: %s.\n", msg);

      if (priv->pixbuf != 0) {
            g_object_unref (priv->pixbuf);
            priv->pixbuf = 0;
      }

      if (GTK_WIDGET_DRAWABLE (priv->display)) {
            gdk_window_clear (GTK_WIDGET (priv->display)->window);
      }
}

static void
image_loading_cancelled_cb (EogImage *img, gpointer data)
{
      EogScrollViewPrivate *priv;

      priv = EOG_SCROLL_VIEW (data)->priv;

      if (priv->pixbuf != NULL) {
            g_object_unref (priv->pixbuf);
            priv->pixbuf = NULL;
      }

      if (GTK_WIDGET_DRAWABLE (priv->display)) {
            gdk_window_clear (GTK_WIDGET (priv->display)->window);
      }
}
*/
static void
image_changed_cb (EogImage *img, gpointer data)
{
      EogScrollViewPrivate *priv;

      priv = EOG_SCROLL_VIEW (data)->priv;

      if (priv->pixbuf != NULL) {
            g_object_unref (priv->pixbuf);
            priv->pixbuf = NULL;
      }

      priv->pixbuf = eog_image_get_pixbuf (img);

      set_zoom_fit (EOG_SCROLL_VIEW (data));
      check_scrollbar_visibility (EOG_SCROLL_VIEW (data), NULL);

      gtk_widget_queue_draw (GTK_WIDGET (priv->display));
}


/*===================================
         public API
  ---------------------------------*/

/* general properties */
void
eog_scroll_view_set_zoom_upscale (EogScrollView *view, gboolean upscale)
{
      EogScrollViewPrivate *priv;

      g_return_if_fail (EOG_IS_SCROLL_VIEW (view));

      priv = view->priv;

      if (priv->upscale != upscale) {
            priv->upscale = upscale;

            if (priv->zoom_mode == ZOOM_MODE_FIT) {
                  set_zoom_fit (view);
                  gtk_widget_queue_draw (GTK_WIDGET (priv->display));
            }
      }
}

void
eog_scroll_view_set_antialiasing (EogScrollView *view, gboolean state)
{
      EogScrollViewPrivate *priv;
      GdkInterpType new_interp_type;

      g_return_if_fail (EOG_IS_SCROLL_VIEW (view));

      priv = view->priv;

      new_interp_type = state ? GDK_INTERP_BILINEAR : GDK_INTERP_NEAREST;

      if (priv->interp_type != new_interp_type) {
            priv->interp_type = new_interp_type;
            gtk_widget_queue_draw (GTK_WIDGET (priv->display));
      }
}

void
eog_scroll_view_set_transparency (EogScrollView *view, TransparencyStyle style, GdkColor *color)
{
      EogScrollViewPrivate *priv;
      guint32 col = 0;
      guint32 red, green, blue;
      gboolean changed = FALSE;

      g_return_if_fail (EOG_IS_SCROLL_VIEW (view));

      priv = view->priv;

      if (color != NULL) {
            red = (color->red >> 8) << 16;
            green = (color->green >> 8) << 8;
            blue = (color->blue >> 8);
            col = red + green + blue;
      }

      if (priv->transp_style != style) {
            priv->transp_style = style;
            changed = TRUE;
      }

      if (priv->transp_style == TRANSP_COLOR && priv->transp_color != col) {
            priv->transp_color = col;
            changed = TRUE;
      }

      if (changed && priv->pixbuf != NULL && gdk_pixbuf_get_has_alpha (priv->pixbuf)) {
            gtk_widget_queue_draw (GTK_WIDGET (priv->display));
      }
}

/* zoom api */

static double preferred_zoom_levels[] = {
      1.0 / 100, 1.0 / 50, 1.0 / 20,
      1.0 / 10.0, 1.0 / 5.0, 1.0 / 3.0, 1.0 / 2.0, 1.0 / 1.5,
        1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0,
        11.0, 12.0, 13.0, 14.0, 15.0, 16.0, 17.0, 18.0, 19.0, 20.0
};
static const gint n_zoom_levels = (sizeof (preferred_zoom_levels) / sizeof (double));

void
eog_scroll_view_zoom_in (EogScrollView *view, gboolean smooth)
{
      EogScrollViewPrivate *priv;
      double zoom;

      g_return_if_fail (EOG_IS_SCROLL_VIEW (view));

      priv = view->priv;

      if (smooth) {
            zoom = priv->zoom * IMAGE_VIEW_ZOOM_MULTIPLIER;
      }
      else {
            int i;
            int index = -1;

            for (i = 0; i < n_zoom_levels; i++) {
                  if (preferred_zoom_levels [i] - priv->zoom
                              > DOUBLE_EQUAL_MAX_DIFF) {
                        index = i;
                        break;
                  }
            }

            if (index == -1) {
                  zoom = priv->zoom;
            }
            else {
                  zoom = preferred_zoom_levels [i];
            }
      }
      set_zoom (view, zoom, FALSE, 0, 0);

}

void
eog_scroll_view_zoom_out (EogScrollView *view, gboolean smooth)
{
      EogScrollViewPrivate *priv;
      double zoom;

      g_return_if_fail (EOG_IS_SCROLL_VIEW (view));

      priv = view->priv;

      if (smooth) {
            zoom = priv->zoom / IMAGE_VIEW_ZOOM_MULTIPLIER;
      }
      else {
            int i;
            int index = -1;

            for (i = n_zoom_levels - 1; i >= 0; i--) {
                  if (priv->zoom - preferred_zoom_levels [i]
                              > DOUBLE_EQUAL_MAX_DIFF) {
                        index = i;
                        break;
                  }
            }
            if (index == -1) {
                  zoom = priv->zoom;
            }
            else {
                  zoom = preferred_zoom_levels [i];
            }
      }
      set_zoom (view, zoom, FALSE, 0, 0);
}

void
eog_scroll_view_zoom_fit (EogScrollView *view)
{
      g_return_if_fail (EOG_IS_SCROLL_VIEW (view));

      set_zoom_fit (view);
      check_scrollbar_visibility (view, NULL);
      gtk_widget_queue_draw (GTK_WIDGET (view->priv->display));
}

void
eog_scroll_view_set_zoom (EogScrollView *view, double zoom)
{
      g_return_if_fail (EOG_IS_SCROLL_VIEW (view));

      set_zoom (view, zoom, FALSE, 0, 0);
}

double
eog_scroll_view_get_zoom (EogScrollView *view)
{
      g_return_val_if_fail (EOG_IS_SCROLL_VIEW (view), 0.0);

      return view->priv->zoom;
}

gboolean
eog_scroll_view_get_zoom_is_min (EogScrollView *view)
{
      g_return_val_if_fail (EOG_IS_SCROLL_VIEW (view), FALSE);

      set_minimum_zoom_factor (view);

      return DOUBLE_EQUAL (view->priv->zoom, MIN_ZOOM_FACTOR) || 
             DOUBLE_EQUAL (view->priv->zoom, view->priv->min_zoom);
}

gboolean
eog_scroll_view_get_zoom_is_max (EogScrollView *view)
{
      g_return_val_if_fail (EOG_IS_SCROLL_VIEW (view), FALSE);

      return DOUBLE_EQUAL (view->priv->zoom, MAX_ZOOM_FACTOR);
}

void
eog_scroll_view_set_image (EogScrollView *view, EogImage *image)
{
      EogScrollViewPrivate *priv;

      g_return_if_fail (EOG_IS_SCROLL_VIEW (view));

      priv = view->priv;

      if (priv->image == image) {
            return;
      }

      if (priv->image != NULL) {
            free_image_resources (view);
            if (GTK_WIDGET_DRAWABLE (priv->display) && image == NULL) {
                  gdk_window_clear (GTK_WIDGET (priv->display)->window);
            }
      }
      g_assert (priv->image == NULL);
      g_assert (priv->pixbuf == NULL);

      priv->progressive_state = PROGRESSIVE_NONE;
      if (image != NULL) {
            eog_image_data_ref (image);

            if (priv->pixbuf == NULL) {
                  priv->pixbuf = eog_image_get_pixbuf (image);
                  priv->progressive_state = PROGRESSIVE_NONE;
                  set_zoom_fit (view);
                  check_scrollbar_visibility (view, NULL);
                  gtk_widget_queue_draw (GTK_WIDGET (priv->display));

            }
            else if (priv->interp_type != GDK_INTERP_NEAREST &&
                   !is_unity_zoom (view))
            {
                  /* paint antialiased image version */
                  priv->progressive_state = PROGRESSIVE_POLISHING;
                  gtk_widget_queue_draw (GTK_WIDGET (priv->display));
            }

            priv->image_changed_id = g_signal_connect (image, "image_changed",
                                             (GCallback) image_changed_cb, view);
      }
      
      priv->image = image;
}

void
eog_scroll_view_get_image_size   (EogScrollView *view, int *width, int *height, gboolean scaled)
{
      EogScrollViewPrivate *priv;

      *width = *height = 0;

      g_return_if_fail (EOG_IS_SCROLL_VIEW (view));

      priv = view->priv;

      if (!priv->pixbuf)
            return;

      *width = gdk_pixbuf_get_width (priv->pixbuf);
      *height = gdk_pixbuf_get_height (priv->pixbuf);
}

gboolean 
eog_scroll_view_scrollbars_visible (EogScrollView *view)
{
      if (!GTK_WIDGET_VISIBLE (GTK_WIDGET (view->priv->hbar)) && 
          !GTK_WIDGET_VISIBLE (GTK_WIDGET (view->priv->vbar)))
            return FALSE;

      return TRUE;
}

/*===================================
    object creation/freeing
  ---------------------------------*/


static void
eog_scroll_view_init (EogScrollView *view)
{
      EogScrollViewPrivate *priv;

      priv = g_new0 (EogScrollViewPrivate, 1);
      view->priv = priv;

      priv->zoom = 1.0;
      priv->min_zoom = MIN_ZOOM_FACTOR;
      priv->zoom_mode = ZOOM_MODE_FIT;
      priv->upscale = FALSE;
      priv->uta = NULL;
      priv->interp_type = GDK_INTERP_BILINEAR;
      priv->image = NULL;
      priv->pixbuf = NULL;
      priv->progressive_state = PROGRESSIVE_NONE;
      priv->transp_style = TRANSP_BACKGROUND;
      priv->transp_color = 0;
      priv->cursor_type = CURSOR_DEFAULT;
}

static void
eog_scroll_view_dispose (GObject *object)
{
      EogScrollView *view;
      EogScrollViewPrivate *priv;

      g_return_if_fail (EOG_IS_SCROLL_VIEW (object));

      view = EOG_SCROLL_VIEW (object);
      priv = view->priv;
      
      if (priv->uta != NULL) {
            art_uta_free (priv->uta);
            priv->uta = NULL;
      }

      if (priv->idle_id != 0) {
            g_source_remove (priv->idle_id);
            priv->idle_id = 0;
      }

      free_image_resources (view);

      G_OBJECT_CLASS (eog_scroll_view_parent_class)->dispose (object);
}

static void
eog_scroll_view_finalize (GObject *object)
{
      EogScrollView *view;

      view = EOG_SCROLL_VIEW (object);
      if (view->priv != 0) {
            g_free (view->priv);
            view->priv = 0;
      }

      G_OBJECT_CLASS (eog_scroll_view_parent_class)->finalize (object);
}

static void
eog_scroll_view_class_init (EogScrollViewClass *klass)
{
      GObjectClass *gobject_class;
      GtkWidgetClass *widget_class;

      gobject_class = (GObjectClass*) klass;
      widget_class = (GtkWidgetClass*) klass;

      gobject_class->dispose = eog_scroll_view_dispose;
      gobject_class->finalize = eog_scroll_view_finalize;


      view_signals [SIGNAL_ZOOM_CHANGED] =
            g_signal_new ("zoom_changed",
                        G_TYPE_OBJECT,
                        G_SIGNAL_RUN_LAST,
                        G_STRUCT_OFFSET (EogScrollViewClass, zoom_changed),
                        NULL, NULL,
                        libeog_marshal_VOID__DOUBLE,
                        G_TYPE_NONE, 1,
                        G_TYPE_DOUBLE);

      widget_class->size_allocate = eog_scroll_view_size_allocate;
      widget_class->style_set = eog_scroll_view_style_set;
}


GtkWidget*
eog_scroll_view_new (void)
{
      GtkWidget *widget;
      GtkTable *table;
      EogScrollView *view;
      EogScrollViewPrivate *priv;

      widget = g_object_new (EOG_TYPE_SCROLL_VIEW,
                         "can-focus", TRUE,
                         "n_rows", 2,
                         "n_columns", 2,
                         "homogeneous", FALSE,
                         NULL);

      table = GTK_TABLE (widget);
      view = EOG_SCROLL_VIEW (widget);
      priv = view->priv;

      priv->hadj = GTK_ADJUSTMENT (gtk_adjustment_new (0, 100, 0, 10, 10, 100));
      g_signal_connect (priv->hadj, "value_changed",
                    G_CALLBACK (adjustment_changed_cb),
                    view);
      priv->hbar = gtk_hscrollbar_new (priv->hadj);
      priv->vadj = GTK_ADJUSTMENT (gtk_adjustment_new (0, 100, 0, 10, 10, 100));
      g_signal_connect (priv->vadj, "value_changed",
                    G_CALLBACK (adjustment_changed_cb),
                    view);
      priv->vbar = gtk_vscrollbar_new (priv->vadj);
      priv->display = g_object_new (GTK_TYPE_DRAWING_AREA,
                              "can-focus", TRUE,
                              NULL);
      /* We don't want to be double-buffered as we are SuperSmart(tm) */
      gtk_widget_set_double_buffered (GTK_WIDGET (priv->display), FALSE);

      gtk_widget_add_events (GTK_WIDGET (priv->display),
                         GDK_EXPOSURE_MASK
                         | GDK_BUTTON_PRESS_MASK
                         | GDK_BUTTON_RELEASE_MASK
                         | GDK_POINTER_MOTION_MASK
                         | GDK_POINTER_MOTION_HINT_MASK
                         | GDK_SCROLL_MASK
                         | GDK_KEY_PRESS_MASK);
      g_signal_connect (G_OBJECT (priv->display), "configure_event", G_CALLBACK (display_size_change), view);
      g_signal_connect (G_OBJECT (priv->display), "expose_event", G_CALLBACK (display_expose_event), view);
      g_signal_connect (G_OBJECT (priv->display), "map_event", G_CALLBACK (display_map_event), view);
      g_signal_connect (G_OBJECT (priv->display), "button_press_event", G_CALLBACK (eog_scroll_view_button_press_event), view);
      g_signal_connect (G_OBJECT (priv->display), "motion_notify_event", G_CALLBACK (eog_scroll_view_motion_event), view);
      g_signal_connect (G_OBJECT (priv->display), "button_release_event", G_CALLBACK (eog_scroll_view_button_release_event), view);
      g_signal_connect (G_OBJECT (priv->display), "scroll_event", G_CALLBACK (eog_scroll_view_scroll_event), view);
      g_signal_connect (G_OBJECT (priv->display), "focus_in_event", G_CALLBACK (eog_scroll_view_focus_in_event), NULL);
      g_signal_connect (G_OBJECT (priv->display), "focus_out_event", G_CALLBACK (eog_scroll_view_focus_out_event), NULL);

      g_signal_connect (G_OBJECT (widget), "key_press_event", G_CALLBACK (display_key_press_event), view);

      gtk_table_attach (table, priv->display,
                    0, 1, 0, 1,
                    GTK_EXPAND | GTK_FILL,
                    GTK_EXPAND | GTK_FILL,
                    0,0);
      gtk_table_attach (table, priv->hbar,
                    0, 1, 1, 2,
                    GTK_FILL,
                    GTK_FILL,
                    0, 0);
      gtk_table_attach (table, priv->vbar,
                    1, 2, 0, 1,
                    GTK_FILL, GTK_FILL,
                    0, 0);

      gtk_widget_show_all (widget);
      
      return widget;
}

Generated by  Doxygen 1.6.0   Back to index