Implement a mostly working InfoBubble with a shim BookmarkBubble.

chrome/browser/gtk/info_bubble_gtk.cc

+// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/gtk/info_bubble_gtk.h"
+
+#include <gtk/gtk.h>
+
+#include "base/basictypes.h"
+#include "base/gfx/gtk_util.h"
+#include "base/gfx/rect.h"
+#include "base/logging.h"
+#include "chrome/common/gfx/path.h"
+
+namespace {
+
+// The height of the arrow, and the width will be about twice the height.
+const int kArrowSize = 5;
+// Number of pixels to the start of the arrow from the edge of the window.
+const int kArrowX = 13;
+// Number of pixels between the tip of the arrow and the region we're
+// pointing to.
+const int kArrowToContentPadding = -6;
+// We draw flat diagonal corners, each corner is an NxN square.
+const int kCornerSize = 3;
+// Margins around the content.
+const int kTopMargin = kArrowSize + kCornerSize + 6;
+const int kBottomMargin = kCornerSize + 6;
+const int kLeftMargin = kCornerSize + 6;
+const int kRightMargin = kCornerSize + 6;
+
+const GdkColor kBackgroundColor = GDK_COLOR_RGB(0xff, 0xff, 0xff);
+const GdkColor kFrameColor = GDK_COLOR_RGB(0x63, 0x63, 0x63);
+
+// A small convenience since GdkPoint is a POD without a constructor.
+GdkPoint MakeGdkPoint(gint x, gint y) {
+  GdkPoint point = {x, y};
+  return point;
+}
+
+enum FrameType {
+  FRAME_MASK,
+  FRAME_STROKE,
+};
+
+// Make the points for our polygon frame, either for fill (the mask), or for
+// when we stroke the border.  NOTE: This seems a bit overcomplicated, but it
+// requires a bunch of careful fudging to get the pixels rasterized exactly
+// where we want them, the arrow to have a 1 pixel point, etc.
+// TODO(deanm): Windows draws with Skia and uses some PNG images for the
+// corners.  This is a lot more work, but they get anti-aliasing.
+std::vector<GdkPoint> MakeFramePolygonPoints(int width,
+                                             int height,
+                                             FrameType type) {
+  std::vector<GdkPoint> points;
+
+  // If we have a stroke, we have to offset some of our points by 1 pixel.
+  int off = (type == FRAME_MASK) ? 0 : 1;
+
+  // Top left corner.
+  points.push_back(MakeGdkPoint(0, kArrowSize + kCornerSize - 1));
+  points.push_back(MakeGdkPoint(kCornerSize - 1, kArrowSize));
+
+  // The arrow.
+  points.push_back(MakeGdkPoint(kArrowX - kArrowSize, kArrowSize));
+  points.push_back(MakeGdkPoint(kArrowX, 0));
+  points.push_back(MakeGdkPoint(kArrowX + 1 - off, 0));
+  points.push_back(MakeGdkPoint(kArrowX + kArrowSize + 1 - off, kArrowSize));
+
+  // Top right corner.
+  points.push_back(MakeGdkPoint(width - kCornerSize + 1 - off, kArrowSize));
+  points.push_back(MakeGdkPoint(width - off, kArrowSize + kCornerSize - 1));
+
+  // Bottom right corner.
+  points.push_back(MakeGdkPoint(width - off, height - kCornerSize));
+  points.push_back(MakeGdkPoint(width - kCornerSize, height - off));
+
+  // Bottom left corner.
+  points.push_back(MakeGdkPoint(kCornerSize - off, height - off));
+  points.push_back(MakeGdkPoint(0, height - kCornerSize));
+
+  return points;
+}
+
+// When our size is initially allocated or changed, we need to recompute
+// and apply our shape mask region.
+void HandleSizeAllocate(GtkWidget* widget,
+                        GtkAllocation* allocation,
+                        gpointer unused) {
+  DCHECK(allocation->x == 0 && allocation->y == 0);
+  std::vector<GdkPoint> points = MakeFramePolygonPoints(
+      allocation->width, allocation->height, FRAME_MASK);
+  GdkRegion* mask_region = gdk_region_polygon(&points[0],
+                                              points.size(),
+                                              GDK_EVEN_ODD_RULE);
+  gdk_window_shape_combine_region(widget->window, mask_region, 0, 0);
+  gdk_region_destroy(mask_region);
+}
+
+gboolean HandleExpose(GtkWidget* widget,
+                      GdkEventExpose* event,
+                      gpointer unused) {
+  GdkDrawable* drawable = GDK_DRAWABLE(event->window);
+  GdkGC* gc = gdk_gc_new(drawable);
+  gdk_gc_set_rgb_fg_color(gc, &kFrameColor);
+
+  // Stroke the frame border.
+  std::vector<GdkPoint> points = MakeFramePolygonPoints(
+      widget->allocation.width, widget->allocation.height, FRAME_STROKE);
+  gdk_draw_polygon(drawable, gc, FALSE, &points[0], points.size());
+
+  g_object_unref(gc);
+  return FALSE;  // Propagate so our children paint, etc.
+}
+
+}  // namespace
+
+// static
+InfoBubbleGtk* InfoBubbleGtk::Show(const gfx::Rect& rect, GtkWidget* content) {
+  InfoBubbleGtk* bubble = new InfoBubbleGtk();
+  bubble->Init(rect, content);
+  return bubble;
+}
+
+InfoBubbleGtk::InfoBubbleGtk()
+    : window_(NULL),
+      screen_x_(0),
+      screen_y_(0),
+      closed_(false) {
+}
+
+InfoBubbleGtk::~InfoBubbleGtk() {
+}
+
+void InfoBubbleGtk::Init(const gfx::Rect& rect, GtkWidget* content) {
+  DCHECK(!window_);
+  screen_x_ = rect.x() + (rect.width() / 2) - kArrowX;
+  screen_y_ = rect.y() + rect.height() + kArrowToContentPadding;
+
+  window_ = gtk_window_new(GTK_WINDOW_TOPLEVEL);
+  gtk_window_set_decorated(GTK_WINDOW(window_), TRUE);
+  gtk_window_set_resizable(GTK_WINDOW(window_), FALSE);
+  gtk_widget_set_app_paintable(window_, TRUE);
+  // Have GTK double buffer around the expose signal.
+  gtk_widget_set_double_buffered(window_, TRUE);
+  // Set the background color, so we don't need to paint it manually.
+  gtk_widget_modify_bg(window_, GTK_STATE_NORMAL, &kBackgroundColor);
+  // Make sure that our window can be focused.
+  GTK_WIDGET_SET_FLAGS(window_, GTK_CAN_FOCUS);
+
+  GtkWidget* alignment = gtk_alignment_new(0.0, 0.0, 1.0, 1.0);
+  gtk_alignment_set_padding(GTK_ALIGNMENT(alignment),
+                            kTopMargin, kBottomMargin,
+                            kLeftMargin, kRightMargin);
+
+  gtk_container_add(GTK_CONTAINER(alignment), content);
+  gtk_container_add(GTK_CONTAINER(window_), alignment);
+
+  // GtkWidget only exposes the bitmap mask interface.  Use GDK to more
+  // efficently mask a GdkRegion.  Make sure the window is realized during
+  // HandleSizeAllocate, so the mask can be applied to the GdkWindow.
+  gtk_widget_realize(window_);
+  gtk_window_move(GTK_WINDOW(window_), screen_x_, screen_y_);
+
+  gtk_widget_add_events(window_, GDK_BUTTON_PRESS_MASK |
+                                 GDK_BUTTON_RELEASE_MASK);
+
+  g_signal_connect(window_, "size-allocate",
+                   G_CALLBACK(HandleSizeAllocate), NULL);
+  g_signal_connect(window_, "expose-event",
+                   G_CALLBACK(HandleExpose), NULL);
+  g_signal_connect(window_, "configure-event",
+                   G_CALLBACK(&HandleConfigureThunk), this);
+  g_signal_connect(window_, "button-press-event",
+                   G_CALLBACK(&HandleButtonPressThunk), this);
+
+  gtk_widget_show_all(window_);
+  gtk_window_present(GTK_WINDOW(window_));
+  gtk_grab_add(window_);
+}
+
+void InfoBubbleGtk::Close() {
+  DCHECK(!closed_);
+  DCHECK(window_);
+  gtk_widget_destroy(window_);
+  window_ = NULL;
+  closed_ = true;
+}
+
+gboolean InfoBubbleGtk::HandleConfigure(GdkEventConfigure* event) {
+  // If the window is moved someplace besides where we want it, move it back.
+  // TODO(deanm): In the end, I will probably remove this code and just let
+  // the user move around the bubble like a normal dialog.  I want to try
+  // this for now and see if it causes problems when any window managers.
+  if (event->x != screen_x_ || event->y != screen_y_)
+    gtk_window_move(GTK_WINDOW(window_), screen_x_, screen_y_);
+  return FALSE;
+}
+
+gboolean InfoBubbleGtk::HandleButtonPress(GdkEventButton* event) {
+  // If we got a click in our own window, that's ok.
+  if (event->window == window_->window)
+    return FALSE;  // Propagate.
+
+  // Otherwise we had a click outside of our window, close ourself.
+  Close();
+  return TRUE;
+}