Bug 560903 – Explicit zooming with e.g. '1' should handle

zoom-focus better

* app/display/display-enums.h: Added
GIMP_ZOOM_FOCUS_RETAIN_CENTERING_ELSE_BEST_GUESS.

* app/display/gimpdisplayshell-scale.c
(gimp_display_shell_scale_get_zoom_focus): Take the new enum into
account; if the image is centered, keep it centered, else use the
best-guess method.

* app/actions/view-commands.c (view_zoom_explicit_cmd_callback):
Use the new enum for explicit zooming.

* app/display/display-enums.c: Regenerated.

svn path=/trunk/; revision=27653

ChangeLog

@@ -1,3 +1,21 @@
+2008-11-15  Martin Nordholts  <martinn@svn.gnome.org>
+
+	Bug 560903 – Explicit zooming with e.g. '1' should handle
+	zoom-focus better
+
+	* app/display/display-enums.h: Added
+	GIMP_ZOOM_FOCUS_RETAIN_CENTERING_ELSE_BEST_GUESS.
+
+	* app/display/gimpdisplayshell-scale.c
+	(gimp_display_shell_scale_get_zoom_focus): Take the new enum into
+	account; if the image is centered, keep it centered, else use the
+	best-guess method.
+
+	* app/actions/view-commands.c (view_zoom_explicit_cmd_callback):
+	Use the new enum for explicit zooming.
+
+	* app/display/display-enums.c: Regenerated.
+
 2008-11-15  Martin Nordholts  <martinn@svn.gnome.org>
 
 	Bug 560245 – Zoom selection always centered in the Navigation tab

app/actions/view-commands.c

@@ -220,7 +220,7 @@ view_zoom_explicit_cmd_callback (GtkAction *action,
         gimp_display_shell_scale (shell,
                                   GIMP_ZOOM_TO,
                                   (gdouble) value / 10000,
-                                  GIMP_ZOOM_FOCUS_IMAGE_CENTER);
+                                  GIMP_ZOOM_FOCUS_RETAIN_CENTERING_ELSE_BEST_GUESS);
     }
 }
 

app/display/display-enums.c

@@ -171,6 +171,7 @@ gimp_zoom_focus_get_type (void)
     { GIMP_ZOOM_FOCUS_BEST_GUESS, "GIMP_ZOOM_FOCUS_BEST_GUESS", "best-guess" },
     { GIMP_ZOOM_FOCUS_POINTER, "GIMP_ZOOM_FOCUS_POINTER", "pointer" },
     { GIMP_ZOOM_FOCUS_IMAGE_CENTER, "GIMP_ZOOM_FOCUS_IMAGE_CENTER", "image-center" },
+    { GIMP_ZOOM_FOCUS_RETAIN_CENTERING_ELSE_BEST_GUESS, "GIMP_ZOOM_FOCUS_RETAIN_CENTERING_ELSE_BEST_GUESS", "retain-centering-else-best-guess" },
     { 0, NULL, NULL }
   };
 
@@ -179,6 +180,7 @@ gimp_zoom_focus_get_type (void)
     { GIMP_ZOOM_FOCUS_BEST_GUESS, "GIMP_ZOOM_FOCUS_BEST_GUESS", NULL },
     { GIMP_ZOOM_FOCUS_POINTER, "GIMP_ZOOM_FOCUS_POINTER", NULL },
     { GIMP_ZOOM_FOCUS_IMAGE_CENTER, "GIMP_ZOOM_FOCUS_IMAGE_CENTER", NULL },
+    { GIMP_ZOOM_FOCUS_RETAIN_CENTERING_ELSE_BEST_GUESS, "GIMP_ZOOM_FOCUS_RETAIN_CENTERING_ELSE_BEST_GUESS", NULL },
     { 0, NULL, NULL }
   };
 

app/display/display-enums.h

@@ -87,9 +87,20 @@ GType gimp_zoom_focus_get_type (void) G_GNUC_CONST;
 
 typedef enum
 {
-  GIMP_ZOOM_FOCUS_BEST_GUESS,    /* Make a best guess                       */
+  /* Make a best guess */
-  GIMP_ZOOM_FOCUS_POINTER,       /* Use the mouse cursor (if within canvas) */
+  GIMP_ZOOM_FOCUS_BEST_GUESS,
-  GIMP_ZOOM_FOCUS_IMAGE_CENTER   /* Use the image center                    */
+
+  /* Use the mouse cursor (if within canvas) */
+  GIMP_ZOOM_FOCUS_POINTER,
+
+  /* Use the image center */
+  GIMP_ZOOM_FOCUS_IMAGE_CENTER,
+
+  /* If the image is centered, retain the centering. Else use
+   * _BEST_GUESS
+   */
+  GIMP_ZOOM_FOCUS_RETAIN_CENTERING_ELSE_BEST_GUESS
+
 } GimpZoomFocus;
 
 

app/display/gimpdisplayshell-scale.c

@@ -61,7 +61,7 @@ static gboolean  gimp_display_shell_scale_image_starts_to_fit
                                                           gdouble           current_scale,
                                                           gboolean         *vertically,
                                                           gboolean         *horizontally);
-static void      gimp_display_shell_scale_viewport_coord_almost_centered
+static gboolean  gimp_display_shell_scale_viewport_coord_almost_centered
                                                          (GimpDisplayShell *shell,
                                                           gint              x,
                                                           gint              y,
@@ -887,21 +887,28 @@ gimp_display_shell_scale_image_stops_to_fit (GimpDisplayShell *shell,
  * @vertically:
  *
  **/
-static void
+static gboolean
 gimp_display_shell_scale_viewport_coord_almost_centered (GimpDisplayShell *shell,
                                                          gint              x,
                                                          gint              y,
                                                          gboolean         *horizontally,
                                                          gboolean         *vertically)
 {
+  gboolean local_horizontally;
+  gboolean local_vertically;
   gint     center_x = shell->disp_width  / 2;
   gint     center_y = shell->disp_height / 2;
 
-  *horizontally = x > center_x - ALMOST_CENTERED_THRESHOLD &&
+  local_horizontally = (x > center_x - ALMOST_CENTERED_THRESHOLD &&
-                  x < center_x + ALMOST_CENTERED_THRESHOLD;
+                        x < center_x + ALMOST_CENTERED_THRESHOLD);
 
-  *vertically   = y > center_y - ALMOST_CENTERED_THRESHOLD &&
+  local_vertically   = (y > center_y - ALMOST_CENTERED_THRESHOLD &&
-                  y < center_y + ALMOST_CENTERED_THRESHOLD;
+                        y < center_y + ALMOST_CENTERED_THRESHOLD);
+
+  if (horizontally) *horizontally = local_horizontally;
+  if (vertically)   *vertically   = local_vertically;
+
+  return local_horizontally && local_vertically;
 }
 
 static void
@@ -937,6 +944,7 @@ gimp_display_shell_scale_get_zoom_focus (GimpDisplayShell *shell,
                                          gint             *y,
                                          GimpZoomFocus     zoom_focus)
 {
+  GimpZoomFocus real_zoom_focus = zoom_focus;
   gint          image_center_x, image_center_y;
   gint          other_x, other_y;
 
@@ -995,7 +1003,25 @@ gimp_display_shell_scale_get_zoom_focus (GimpDisplayShell *shell,
   }
 
   /* Decide which one to use for each axis */
-  switch (zoom_focus)
+  if (zoom_focus == GIMP_ZOOM_FOCUS_RETAIN_CENTERING_ELSE_BEST_GUESS)
+    {
+      gboolean centered;
+
+      centered = gimp_display_shell_scale_viewport_coord_almost_centered (shell,
+                                                                          image_center_x,
+                                                                          image_center_y,
+                                                                          NULL,
+                                                                          NULL);
+      real_zoom_focus = (centered ?
+                         GIMP_ZOOM_FOCUS_IMAGE_CENTER :
+                         GIMP_ZOOM_FOCUS_BEST_GUESS);
+    }
+  else
+    {
+      real_zoom_focus = zoom_focus;
+    }
+
+  switch (real_zoom_focus)
     {
     case GIMP_ZOOM_FOCUS_POINTER:
       *x = other_x;