[nautilus] nautilus-canvas-container: Remove the "include visible area" logic.

[Carlos Soriano <csoriano src gnome org>]

commit a7a31137aee8c4af81d7d447ceb83ccdb2ddadc0
Author: Xiang Fan <sfanxiang gmail com>
Date:   Fri Jul 13 11:49:09 2018 -0700

    nautilus-canvas-container: Remove the "include visible area" logic.
    
    canvas_set_scroll_region_include_visible_area() was added in
    ec054c80981e26b71c8bb2e6853b035dc2063e7d to fix
    https://bugzilla.gnome.org/show_bug.cgi?id=42068 ("Dragging icons
    adjusts scroll area in a way that causes immediate scrolling"). This is
    no longer the case, because now icons remain in place when being dragged
    and are not allowed to be rearranged.
    
    ec054c80981e26b71c8bb2e6853b035dc2063e7d causes issues relating to extra
    scrolling space (#340), hence the removal.
    
    Fixes #340.

 src/nautilus-canvas-container.c | 79 +----------------------------------------
 src/nautilus-canvas-container.h |  1 -
 src/nautilus-canvas-private.h   |  3 --
 src/nautilus-canvas-view.c      |  6 ----
 4 files changed, 1 insertion(+), 88 deletions(-)
---
diff --git a/src/nautilus-canvas-container.c b/src/nautilus-canvas-container.c
index 09acd47fc..bd05a3a2d 100644
--- a/src/nautilus-canvas-container.c
+++ b/src/nautilus-canvas-container.c
@@ -968,45 +968,6 @@ get_all_icon_bounds (NautilusCanvasContainer       *container,
                                        x1, y1, x2, y2, usage);
 }
 
-/* Don't preserve visible white space the next time the scroll region
- * is recomputed when the container is not empty. */
-void
-nautilus_canvas_container_reset_scroll_region (NautilusCanvasContainer *container)
-{
-    container->details->reset_scroll_region_trigger = TRUE;
-}
-
-/* Set a new scroll region without eliminating any of the currently-visible area. */
-static void
-canvas_set_scroll_region_include_visible_area (EelCanvas *canvas,
-                                               double     x1,
-                                               double     y1,
-                                               double     x2,
-                                               double     y2)
-{
-    double old_x1, old_y1, old_x2, old_y2;
-    double old_scroll_x, old_scroll_y;
-    double height, width;
-    GtkAllocation allocation;
-
-    eel_canvas_get_scroll_region (canvas, &old_x1, &old_y1, &old_x2, &old_y2);
-    gtk_widget_get_allocation (GTK_WIDGET (canvas), &allocation);
-
-    width = (allocation.width) / canvas->pixels_per_unit;
-    height = (allocation.height) / canvas->pixels_per_unit;
-
-    old_scroll_x = gtk_adjustment_get_value (gtk_scrollable_get_hadjustment (GTK_SCROLLABLE (canvas)));
-    old_scroll_y = gtk_adjustment_get_value (gtk_scrollable_get_vadjustment (GTK_SCROLLABLE (canvas)));
-
-    x1 = MIN (x1, old_x1 + old_scroll_x);
-    y1 = MIN (y1, old_y1 + old_scroll_y);
-    x2 = MAX (x2, old_x1 + old_scroll_x + width);
-    y2 = MAX (y2, old_y1 + old_scroll_y + height);
-
-    eel_canvas_set_scroll_region
-        (canvas, x1, y1, x2, y2);
-}
-
 void
 nautilus_canvas_container_update_scroll_region (NautilusCanvasContainer *container)
 {
@@ -1014,24 +975,10 @@ nautilus_canvas_container_update_scroll_region (NautilusCanvasContainer *contain
     double pixels_per_unit;
     GtkAdjustment *hadj, *vadj;
     float step_increment;
-    gboolean reset_scroll_region;
     GtkAllocation allocation;
 
     pixels_per_unit = EEL_CANVAS (container)->pixels_per_unit;
 
-    reset_scroll_region = container->details->reset_scroll_region_trigger
-                          || nautilus_canvas_container_is_empty (container);
-
-    /* The trigger is only cleared when container is non-empty, so
-     * callers can reliably reset the scroll region when an item
-     * is added even if extraneous relayouts are called when the
-     * window is still empty.
-     */
-    if (!nautilus_canvas_container_is_empty (container))
-    {
-        container->details->reset_scroll_region_trigger = FALSE;
-    }
-
     get_all_icon_bounds (container, &x1, &y1, &x2, &y2, BOUNDS_USAGE_FOR_ENTIRE_ITEM);
 
     /* Add border at the "end"of the layout (i.e. after the icons), to
@@ -1053,18 +1000,7 @@ nautilus_canvas_container_update_scroll_region (NautilusCanvasContainer *contain
     y2 -= 1;
     y2 = MAX (y1, y2);
 
-    if (reset_scroll_region)
-    {
-        eel_canvas_set_scroll_region
-            (EEL_CANVAS (container),
-            x1, y1, x2, y2);
-    }
-    else
-    {
-        canvas_set_scroll_region_include_visible_area
-            (EEL_CANVAS (container),
-            x1, y1, x2, y2);
-    }
+    eel_canvas_set_scroll_region (EEL_CANVAS (container), x1, y1, x2, y2);
 
     hadj = gtk_scrollable_get_hadjustment (GTK_SCROLLABLE (container));
     vadj = gtk_scrollable_get_vadjustment (GTK_SCROLLABLE (container));
@@ -5722,23 +5658,10 @@ nautilus_canvas_container_get_icon_drop_target_uri (NautilusCanvasContainer *con
     return uri;
 }
 
-/* Call to reset the scroll region only if the container is not empty,
- * to avoid having the flag linger until the next file is added.
- */
-static void
-reset_scroll_region_if_not_empty (NautilusCanvasContainer *container)
-{
-    if (!nautilus_canvas_container_is_empty (container))
-    {
-        nautilus_canvas_container_reset_scroll_region (container);
-    }
-}
-
 /* Re-sort, switching to automatic layout if it was in manual layout. */
 void
 nautilus_canvas_container_sort (NautilusCanvasContainer *container)
 {
-    reset_scroll_region_if_not_empty (container);
     container->details->needs_resort = TRUE;
     redo_layout (container);
 }
diff --git a/src/nautilus-canvas-container.h b/src/nautilus-canvas-container.h
index a370bba26..33929375d 100644
--- a/src/nautilus-canvas-container.h
+++ b/src/nautilus-canvas-container.h
@@ -271,7 +271,6 @@ void              nautilus_canvas_container_set_single_click_mode         (Nauti
                                                                           gboolean                
single_click_mode);
 void              nautilus_canvas_container_enable_linger_selection       (NautilusCanvasContainer  *view,
                                                                           gboolean                enable);
-void              nautilus_canvas_container_reset_scroll_region           (NautilusCanvasContainer  
*container);
 void              nautilus_canvas_container_set_font                      (NautilusCanvasContainer  
*container,
                                                                           const char             *font); 
 void              nautilus_canvas_container_set_margins                   (NautilusCanvasContainer  
*container,
diff --git a/src/nautilus-canvas-private.h b/src/nautilus-canvas-private.h
index dd5e79060..e60e86299 100644
--- a/src/nautilus-canvas-private.h
+++ b/src/nautilus-canvas-private.h
@@ -192,9 +192,6 @@ struct NautilusCanvasContainerDetails {
 
        int size_allocation_count;
        guint size_allocation_count_id;
-       
-       /* Ignore the visible area the next time the scroll region is recomputed */
-       gboolean reset_scroll_region_trigger;
 
        /* a11y items used by canvas items */
        guint a11y_item_action_idle_handler;
diff --git a/src/nautilus-canvas-view.c b/src/nautilus-canvas-view.c
index f74ea06db..bd3a7ae5d 100644
--- a/src/nautilus-canvas-view.c
+++ b/src/nautilus-canvas-view.c
@@ -355,12 +355,6 @@ nautilus_canvas_view_add_files (NautilusFilesView *view,
     canvas_view = NAUTILUS_CANVAS_VIEW (view);
     canvas_container = get_canvas_container (canvas_view);
 
-    /* Reset scroll region for the first canvas added when loading a directory. */
-    if (nautilus_files_view_get_loading (view) && nautilus_canvas_container_is_empty (canvas_container))
-    {
-        nautilus_canvas_container_reset_scroll_region (canvas_container);
-    }
-
     for (l = files; l != NULL; l = l->next)
     {
         if (nautilus_canvas_container_add (canvas_container,