[gtk+/wip/baedert/drawing: 3/4] scrolledwindow: Fix child widget positioning

[Timm Bäder <baedert src gnome org>]

commit f24a9d67d433b810689dcae0115b1301c23b0232
Author: Timm Bäder <mail baedert org>
Date:   Sat May 6 11:41:29 2017 +0200

    scrolledwindow: Fix child widget positioning
    
    Instead of relying on get_relative_allocation, just use the
    scrolledwindow's content allocation we get passed to size-allocate.

 gtk/gtkscrolledwindow.c |   55 ++++++++++++++++++++++++++++++++++++++--------
 1 files changed, 45 insertions(+), 10 deletions(-)
---
diff --git a/gtk/gtkscrolledwindow.c b/gtk/gtkscrolledwindow.c
index 5eb9094..828c629 100644
--- a/gtk/gtkscrolledwindow.c
+++ b/gtk/gtkscrolledwindow.c
@@ -340,7 +340,8 @@ static void     gtk_scrolled_window_inner_allocation   (GtkWidget         *widge
 static void     gtk_scrolled_window_allocate_scrollbar (GtkScrolledWindow *scrolled_window,
                                                         GtkWidget         *scrollbar,
                                                         GtkAllocation     *allocation);
-static void     gtk_scrolled_window_allocate_child     (GtkScrolledWindow *swindow);
+static void     gtk_scrolled_window_allocate_child     (GtkScrolledWindow   *swindow,
+                                                        const GtkAllocation *content_allocation);
 static void     gtk_scrolled_window_adjustment_changed (GtkAdjustment     *adjustment,
                                                         gpointer           data);
 static void     gtk_scrolled_window_adjustment_value_changed (GtkAdjustment     *adjustment,
@@ -1581,7 +1582,7 @@ gtk_scrolled_window_size_allocate (GtkWidget     *widget,
        {
          previous_hvis = priv->hscrollbar_visible;
          previous_vvis = priv->vscrollbar_visible;
-         gtk_scrolled_window_allocate_child (scrolled_window);
+         gtk_scrolled_window_allocate_child (scrolled_window, allocation);
 
          /* Explicitly force scrollbar visibility checks.
           *
@@ -1608,7 +1609,7 @@ gtk_scrolled_window_size_allocate (GtkWidget     *widget,
              priv->hscrollbar_visible = TRUE;
              priv->vscrollbar_visible = TRUE;
 
-             gtk_scrolled_window_allocate_child (scrolled_window);
+             gtk_scrolled_window_allocate_child (scrolled_window, allocation);
 
              break;
            }
@@ -3057,20 +3058,54 @@ _gtk_scrolled_window_get_overshoot (GtkScrolledWindow *scrolled_window,
 }
 
 static void
-gtk_scrolled_window_allocate_child (GtkScrolledWindow *swindow)
+gtk_scrolled_window_allocate_child (GtkScrolledWindow   *swindow,
+                                    const GtkAllocation *content_allocation)
 {
+  GtkScrolledWindowPrivate *priv = gtk_scrolled_window_get_instance_private (swindow);
   GtkWidget     *widget = GTK_WIDGET (swindow), *child;
   GtkAllocation  child_allocation;
-  GtkAllocation  relative_allocation;
+  int sb_width;
+  int sb_height;
 
   child = gtk_bin_get_child (GTK_BIN (widget));
 
-  gtk_scrolled_window_relative_allocation (widget, &relative_allocation);
+  child_allocation = *content_allocation;
+  child_allocation.x = 0;
+  child_allocation.y = 0;
 
-  child_allocation.x = relative_allocation.x;
-  child_allocation.y = relative_allocation.y;
-  child_allocation.width = relative_allocation.width;
-  child_allocation.height = relative_allocation.height;
+  /* Get possible scrollbar dimensions */
+  gtk_widget_measure (priv->vscrollbar, GTK_ORIENTATION_HORIZONTAL, -1,
+                      &sb_width, NULL, NULL, NULL);
+  gtk_widget_measure (priv->hscrollbar, GTK_ORIENTATION_VERTICAL, -1,
+                      &sb_height, NULL, NULL, NULL);
+
+  /* Subtract some things from our available allocation size */
+  if (priv->vscrollbar_visible && !priv->use_indicators)
+    {
+      gboolean is_rtl;
+
+      is_rtl = _gtk_widget_get_direction (widget) == GTK_TEXT_DIR_RTL;
+
+      if ((!is_rtl &&
+           (priv->window_placement == GTK_CORNER_TOP_RIGHT ||
+            priv->window_placement == GTK_CORNER_BOTTOM_RIGHT)) ||
+          (is_rtl &&
+           (priv->window_placement == GTK_CORNER_TOP_LEFT ||
+            priv->window_placement == GTK_CORNER_BOTTOM_LEFT)))
+        child_allocation.x += sb_width;
+
+      child_allocation.width = MAX (1, child_allocation.width - sb_width);
+    }
+
+  if (priv->hscrollbar_visible && !priv->use_indicators)
+    {
+
+      if (priv->window_placement == GTK_CORNER_BOTTOM_LEFT ||
+          priv->window_placement == GTK_CORNER_BOTTOM_RIGHT)
+        child_allocation.y += (sb_height);
+
+      child_allocation.height = MAX (1, child_allocation.height - sb_height);
+    }
 
   gtk_widget_size_allocate (child, &child_allocation);
 }