Refactoring of cursor usage (primarily for linux).

Add API to WebCursor to return a native-cursor, and implementation for windows,
linux and mac.

For linux: Move gtk_util::GetCursor into gfx:: namespace. Also, get rid of
ref/unref'ing the cursors from everywhere. Instead, do almost all of it in one
place (in gfx). Also, show proper cursors for web-pages with touchui=1 (i.e. add
support for updating cursor in RenderWidgetHostViewViews).

Review URL: http://codereview.chromium.org/5110010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@67034 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 39 insertions, 0 deletions

diff --git a/gfx/gtk_util.cc b/gfx/gtk_util.cc
index b30b827..96195fe 100644
--- a/gfx/gtk_util.cc
+++ b/gfx/gtk_util.cc
@@ -17,6 +17,40 @@
 
 namespace {
 
+// A process wide singleton that manages our usage of gdk
+// cursors. gdk_cursor_new() hits the disk in several places and GdkCursor
+// instances can be reused throughout the process.
+class GdkCursorCache {
+ public:
+   GdkCursorCache() {}
+  ~GdkCursorCache() {
+    for (std::map<GdkCursorType, GdkCursor*>::iterator it =
+        cursor_cache_.begin(); it != cursor_cache_.end(); ++it) {
+      gdk_cursor_unref(it->second);
+    }
+    cursor_cache_.clear();
+  }
+
+  GdkCursor* GetCursorImpl(GdkCursorType type) {
+    std::map<GdkCursorType, GdkCursor*>::iterator it = cursor_cache_.find(type);
+    GdkCursor* cursor = NULL;
+    if (it == cursor_cache_.end()) {
+      cursor = gdk_cursor_new(type);
+      cursor_cache_.insert(std::make_pair(type, cursor));
+    } else {
+      cursor = it->second;
+    }
+
+    // It is not necessary to add a reference here. The callers can ref the
+    // cursor if they need it for something.
+    return cursor;
+  }
+
+  std::map<GdkCursorType, GdkCursor*> cursor_cache_;
+
+  DISALLOW_COPY_AND_ASSIGN(GdkCursorCache);
+};
+
 void FreePixels(guchar* pixels, gpointer data) {
   free(data);
 }
@@ -146,6 +180,11 @@ double GetPangoResolution() {
   return resolution;
 }
 
+GdkCursor* GetCursor(int type) {
+  static GdkCursorCache impl;
+  return impl.GetCursorImpl(static_cast<GdkCursorType>(type));
+}
+
 std::string ConvertAcceleratorsFromWindowsStyle(const std::string& label) {
   return ConvertAmperstandsTo(label, "_");
 }