Extract MonitorInfoProvider from WindowSizer.

chrome/browser/ui/monitor_info_provider_gtk.cc

+// Copyright (c) 2011 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/ui/monitor_info_provider.h"
+
+#include <gtk/gtk.h>
+
+#include "base/compiler_specific.h"
+#include "base/logging.h"
+
+namespace {
+
+class MonitorInfoProviderGtk : public MonitorInfoProvider {
+ public:
+  MonitorInfoProviderGtk();
+  virtual ~MonitorInfoProviderGtk();
+
+  // Overridden from MonitorInfoProvider:
+  virtual gfx::Rect GetPrimaryMonitorWorkArea() const OVERRIDE;
+  virtual gfx::Rect GetPrimaryMonitorBounds() const OVERRIDE;
+  virtual gfx::Rect GetMonitorWorkAreaMatching(
+      const gfx::Rect& match_rect) const OVERRIDE;
+  virtual void UpdateWorkAreas() OVERRIDE;
+
+ private:
+  // Get the available screen space as a gfx::Rect, or return false if
+  // if it's unavailable (i.e. the window manager doesn't support
+  // retrieving this).
+  // TODO(thestig) Use _NET_CURRENT_DESKTOP here as well?
+  bool GetScreenWorkArea(gfx::Rect* out_rect) const;
+
+  DISALLOW_COPY_AND_ASSIGN(MonitorInfoProviderGtk);
+};
+
+MonitorInfoProviderGtk::MonitorInfoProviderGtk() {
+}
+
+MonitorInfoProviderGtk::~MonitorInfoProviderGtk() {
+}
+
+gfx::Rect MonitorInfoProviderGtk::GetPrimaryMonitorWorkArea() const {
+  gfx::Rect rect;
+  if (GetScreenWorkArea(&rect))
+    return rect.Intersect(GetPrimaryMonitorBounds());
+
+  // Return the best we've got.
+  return GetPrimaryMonitorBounds();
+}
+
+gfx::Rect MonitorInfoProviderGtk::GetPrimaryMonitorBounds() const {
+  GdkScreen* screen = gdk_screen_get_default();
+  GdkRectangle rect;
+  gdk_screen_get_monitor_geometry(screen, 0, &rect);
+  return gfx::Rect(rect);
+}
+
+gfx::Rect MonitorInfoProviderGtk::GetMonitorWorkAreaMatching(
+    const gfx::Rect& match_rect) const {
+  // TODO(thestig) Implement multi-monitor support.
+  return GetPrimaryMonitorWorkArea();
+}
+
+void MonitorInfoProviderGtk::UpdateWorkAreas() {
+  // TODO(thestig) Implement multi-monitor support.
+  work_areas_.clear();
+  work_areas_.push_back(GetPrimaryMonitorBounds());
+}
+
+bool MonitorInfoProviderGtk::GetScreenWorkArea(gfx::Rect* out_rect) const {
+  gboolean ok;
+  guchar* raw_data = NULL;
+  gint data_len = 0;
+  ok = gdk_property_get(gdk_get_default_root_window(),  // a gdk window
+      gdk_atom_intern("_NET_WORKAREA", FALSE),  // property
+      gdk_atom_intern("CARDINAL", FALSE),  // property type
+      0,  // byte offset into property
+      0xff,  // property length to retrieve
+      false,  // delete property after retrieval?
+      NULL,  // returned property type
+      NULL,  // returned data format
+      &data_len,  // returned data len
+      &raw_data);  // returned data
+  if (!ok)
+    return false;
+
+  // We expect to get four longs back: x, y, width, height.
+  if (data_len < static_cast<gint>(4 * sizeof(glong))) {
+    NOTREACHED();
+    g_free(raw_data);
+    return false;
+  }
+
+  glong* data = reinterpret_cast<glong*>(raw_data);
+  gint x = data[0];
+  gint y = data[1];
+  gint width = data[2];
+  gint height = data[3];
+  g_free(raw_data);
+
+  out_rect->SetRect(x, y, width, height);
+  return true;
+}
+
+}  // namespace
+
+// static
+MonitorInfoProvider* MonitorInfoProvider::Create() {
+  return new MonitorInfoProviderGtk();
+}