[gtk/wip/baedert/for-master] layoutoverlay: Fix everything

[Timm Bäder <baedert src gnome org>]

commit 5d91b596fc27f0ed65021d8268e0790bd1003c17
Author: Timm Bäder <mail baedert org>
Date:   Mon Aug 26 19:34:52 2019 +0200

    layoutoverlay: Fix everything
    
    This code is better because:
    
      1) The coordinates translations are actually correct and not sometimes
         wrong like before
      2) We clip widgets that have overflow set
      3) We honor the widget's transform
      4) It is less code

 gtk/inspector/layoutoverlay.c | 137 +++++++++++++++++-------------------------
 1 file changed, 56 insertions(+), 81 deletions(-)
---
diff --git a/gtk/inspector/layoutoverlay.c b/gtk/inspector/layoutoverlay.c
index 5b13b6e6b8..d21b858f5d 100644
--- a/gtk/inspector/layoutoverlay.c
+++ b/gtk/inspector/layoutoverlay.c
@@ -69,10 +69,11 @@ static void
 recurse_child_widgets (GtkWidget   *widget,
                        GtkSnapshot *snapshot)
 {
+  gboolean needs_clip;
+  int width = gtk_widget_get_width (widget);
+  int height = gtk_widget_get_height (widget);
   GtkBorder margin, border, padding;
   GtkBorder widget_margin;
-  GtkAllocation allocation;
-  graphene_rect_t bounds;
   GtkCssStyle *style;
   GtkWidget *child;
 
@@ -90,105 +91,79 @@ recurse_child_widgets (GtkWidget   *widget,
   widget_margin.right = gtk_widget_get_margin_end (widget);
   widget_margin.bottom = gtk_widget_get_margin_bottom (widget);
 
-  gtk_widget_get_allocation (widget, &allocation);
-
+  /* width/height are the content size and we're going to grow that
+   * as we're drawing the boxes, as well as offset the origin.
+   * Right now we're at the widget's own origin.
+   */
   gtk_snapshot_save (snapshot);
-
-  /* Offset for all of the drawing done here. We assume cooridinates relative to
-   * the widget allocation, not the content allocation. */
-  gtk_snapshot_translate (snapshot, &GRAPHENE_POINT_INIT (allocation.x, allocation.y));
-
-  /* Now do all the stuff */
   gtk_snapshot_push_debug (snapshot, "Widget layout debugging");
 
-  /* Widget margins */
-  graphene_rect_init (&bounds,
-                      0, -widget_margin.top,
-                      allocation.width, widget_margin.top);
-  gtk_snapshot_append_color (snapshot, &WIDGET_MARGIN_COLOR, &bounds);
-
-  graphene_rect_init (&bounds,
-                      0, allocation.height,
-                      allocation.width, widget_margin.bottom);
-  gtk_snapshot_append_color (snapshot, &WIDGET_MARGIN_COLOR, &bounds);
-
-  graphene_rect_init (&bounds,
-                      -widget_margin.left, 0,
-                      widget_margin.left, allocation.height);
-  gtk_snapshot_append_color (snapshot, &WIDGET_MARGIN_COLOR, &bounds);
 
-  graphene_rect_init (&bounds,
-                      allocation.width, 0,
-                      widget_margin.right, allocation.height);
-  gtk_snapshot_append_color (snapshot, &WIDGET_MARGIN_COLOR, &bounds);
+  /* CSS Padding */
+  gtk_snapshot_append_color (snapshot, &PADDING_COLOR,
+                             &GRAPHENE_RECT_INIT ( 0, - padding.top, width, padding.top));
+  gtk_snapshot_append_color (snapshot, &PADDING_COLOR,
+                             &GRAPHENE_RECT_INIT (width, 0, padding.right, height));
+  gtk_snapshot_append_color (snapshot, &PADDING_COLOR,
+                             &GRAPHENE_RECT_INIT (0, height, width, padding.bottom));
+  gtk_snapshot_append_color (snapshot, &PADDING_COLOR,
+                             &GRAPHENE_RECT_INIT (- padding.left, 0, padding.left, height));
 
+  /* Grow box + offset */
+  width += padding.left + padding.right;
+  height += padding.top + padding.bottom;
+  gtk_snapshot_translate (snapshot, &GRAPHENE_POINT_INIT (- padding.left, - padding.top));
 
   /* CSS Margins */
-  graphene_rect_init (&bounds,
-                      0, 0,
-                      allocation.width, margin.top);
-  gtk_snapshot_append_color (snapshot, &MARGIN_COLOR, &bounds);
-
-  graphene_rect_init (&bounds,
-                      0, allocation.height - margin.bottom,
-                      allocation.width, margin.bottom);
-  gtk_snapshot_append_color (snapshot, &MARGIN_COLOR, &bounds);
-
-  graphene_rect_init (&bounds,
-                      0, margin.top,
-                      margin.left, allocation.height - margin.top - margin.bottom);
-  gtk_snapshot_append_color (snapshot, &MARGIN_COLOR, &bounds);
-
-  graphene_rect_init (&bounds,
-                      allocation.width - margin.right, margin.top,
-                      margin.right, allocation.height - margin.top - margin.bottom);
-  gtk_snapshot_append_color (snapshot, &MARGIN_COLOR, &bounds);
-
-
-  /* Padding */
-  graphene_rect_init (&bounds,
-                      margin.left + border.left,
-                      margin.top + border.top,
-                      allocation.width - margin.left - margin.right - border.left - border.right,
-                      padding.top);
-  gtk_snapshot_append_color (snapshot, &PADDING_COLOR, &bounds);
-
-  graphene_rect_init (&bounds,
-                      margin.left + border.left,
-                      allocation.height - margin.bottom - border.bottom - padding.bottom,
-                      allocation.width - margin.left - margin.right - border.left - border.right,
-                      padding.bottom);
-  gtk_snapshot_append_color (snapshot, &PADDING_COLOR, &bounds);
-
-  graphene_rect_init (&bounds,
-                      margin.left + border.left,
-                      margin.top + border.top + padding.top,
-                      padding.left,
-                      allocation.height - margin.top - margin.bottom - border.top - border.bottom - 
padding.top - padding.bottom);
-  gtk_snapshot_append_color (snapshot, &PADDING_COLOR, &bounds);
-
-  graphene_rect_init (&bounds,
-                      allocation.width - margin.right - border.right - padding.right,
-                      margin.top + border.top + padding.top,
-                      padding.right,
-                      allocation.height - margin.top - margin.bottom - border.top - border.bottom - 
padding.top - padding.bottom);
-  gtk_snapshot_append_color (snapshot, &PADDING_COLOR, &bounds);
+  gtk_snapshot_append_color (snapshot, &MARGIN_COLOR,
+                             &GRAPHENE_RECT_INIT (0, - margin.top, width, margin.top));
+  gtk_snapshot_append_color (snapshot, &MARGIN_COLOR,
+                             &GRAPHENE_RECT_INIT (width, 0, margin.right, height));
+  gtk_snapshot_append_color (snapshot, &MARGIN_COLOR,
+                             &GRAPHENE_RECT_INIT (0, height, width, margin.bottom));
+  gtk_snapshot_append_color (snapshot, &MARGIN_COLOR,
+                             &GRAPHENE_RECT_INIT (- margin.left, 0, margin.left, height));
+
+  width += margin.left + margin.right;
+  height += margin.top + margin.bottom;
+  gtk_snapshot_translate (snapshot, &GRAPHENE_POINT_INIT (- margin.left, - margin.top));
+
+  /* Widget Margins */
+  gtk_snapshot_append_color (snapshot, &WIDGET_MARGIN_COLOR,
+                             &GRAPHENE_RECT_INIT (0, - widget_margin.top, width, widget_margin.top));
+  gtk_snapshot_append_color (snapshot, &WIDGET_MARGIN_COLOR,
+                             &GRAPHENE_RECT_INIT (width, 0, widget_margin.right, height));
+  gtk_snapshot_append_color (snapshot, &WIDGET_MARGIN_COLOR,
+                             &GRAPHENE_RECT_INIT (0, height, width, widget_margin.bottom));
+  gtk_snapshot_append_color (snapshot, &WIDGET_MARGIN_COLOR,
+                             &GRAPHENE_RECT_INIT (- widget_margin.left, 0, widget_margin.left, height));
 
   gtk_snapshot_pop (snapshot);
 
 
+  needs_clip = gtk_widget_get_overflow (widget) == GTK_OVERFLOW_HIDDEN &&
+               gtk_widget_get_first_child (widget) != NULL;
+
+  if (needs_clip)
+    gtk_snapshot_push_clip (snapshot,
+                            &GRAPHENE_RECT_INIT (0, 0, gtk_widget_get_width (widget), gtk_widget_get_height 
(widget)));
+
   /* Recurse into child widgets */
   for (child = gtk_widget_get_first_child (widget);
        child != NULL;
        child = gtk_widget_get_next_sibling (child))
     {
-      const int offset_x = margin.left + border.left + padding.left;
-      const int offset_y = margin.top + border.top + padding.top;
+      gtk_snapshot_save (snapshot);
+      gtk_snapshot_transform (snapshot, child->priv->transform);
 
-      gtk_snapshot_translate (snapshot, &GRAPHENE_POINT_INIT (offset_x, offset_y));
       recurse_child_widgets (child, snapshot);
+
+      gtk_snapshot_restore (snapshot);
     }
 
+  if (needs_clip)
+    gtk_snapshot_pop (snapshot);
+
   gtk_snapshot_restore (snapshot);
 }