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

[Timm Bäder <baedert src gnome org>]

commit db0560b31466d14f9a46fd4c0b90acd75e4e57be
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 | 155 +++++++++++++++---------------------------
 1 file changed, 56 insertions(+), 99 deletions(-)
---
diff --git a/gtk/inspector/layoutoverlay.c b/gtk/inspector/layoutoverlay.c
index 5b13b6e6b8..4077f80fc5 100644
--- a/gtk/inspector/layoutoverlay.c
+++ b/gtk/inspector/layoutoverlay.c
@@ -6,10 +6,6 @@
 #include "gtkcssnodeprivate.h"
 #include "gtkcssnumbervalueprivate.h"
 
-static const GdkRGBA WIDGET_MARGIN_COLOR = {0.7, 0,   0, 0.6};
-static const GdkRGBA MARGIN_COLOR        = {0.7, 0.7, 0, 0.6};
-static const GdkRGBA PADDING_COLOR       = {0.7, 0, 0.7, 0.6};
-
 struct _GtkLayoutOverlay
 {
   GtkInspectorOverlay parent_instance;
@@ -69,126 +65,87 @@ static void
 recurse_child_widgets (GtkWidget   *widget,
                        GtkSnapshot *snapshot)
 {
-  GtkBorder margin, border, padding;
-  GtkBorder widget_margin;
-  GtkAllocation allocation;
-  graphene_rect_t bounds;
+  gboolean needs_clip;
+  int width = gtk_widget_get_width (widget);
+  int height = gtk_widget_get_height (widget);
   GtkCssStyle *style;
   GtkWidget *child;
+  GtkBorder boxes[4];
+  const GdkRGBA colors[4] = {
+    {0.7, 0.0, 0.7, 0.6}, /* Padding */
+    {0.0, 0.0, 0.0, 0.0}, /* Border */
+    {0.7, 0.7, 0.0, 0.6}, /* CSS Margin */
+    {0.7, 0.0, 0.0, 0.6}, /* Widget Margin */
+  };
+  int i;
 
   if (!gtk_widget_get_mapped (widget))
     return;
 
   style = gtk_css_node_get_style (gtk_widget_get_css_node (widget));
-  get_box_margin (style, &margin);
-  get_box_border (style, &border);
-  get_box_padding (style, &padding);
+  get_box_padding (style, &boxes[0]);
+  get_box_border (style, &boxes[1]);
+  get_box_margin (style, &boxes[2]);
 
   /* TODO: Eh, left = start? RTL? */
-  widget_margin.left = gtk_widget_get_margin_start (widget);
-  widget_margin.top = gtk_widget_get_margin_top (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);
-
+  boxes[3].left = gtk_widget_get_margin_start (widget);
+  boxes[3].top = gtk_widget_get_margin_top (widget);
+  boxes[3].right = gtk_widget_get_margin_end (widget);
+  boxes[3].bottom = gtk_widget_get_margin_bottom (widget);
+
+  /* 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 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);
+  for (i = 0; i < G_N_ELEMENTS (boxes); i ++)
+    {
+      const GdkRGBA *color = &colors[i];
+      const GtkBorder *box = &boxes[i];
+
+      gtk_snapshot_append_color (snapshot, color,
+                                 &GRAPHENE_RECT_INIT ( 0, - box->top, width, box->top));
+      gtk_snapshot_append_color (snapshot, color,
+                                 &GRAPHENE_RECT_INIT (width, 0, box->right, height));
+      gtk_snapshot_append_color (snapshot, color,
+                                 &GRAPHENE_RECT_INIT (0, height, width, box->bottom));
+      gtk_snapshot_append_color (snapshot, color,
+                                 &GRAPHENE_RECT_INIT (- box->left, 0, box->left, height));
+
+      /* Grow box + offset */
+      width += box->left + box->right;
+      height += box->top + box->bottom;
+      gtk_snapshot_translate (snapshot, &GRAPHENE_POINT_INIT (- box->left, - box->top));
+    }
 
   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);
 }