Require a mouse button release event before counting a press event as a new click.

BUG=389162
TEST=EventTest.DoubleClickRequiresRelease

Review URL: https://codereview.chromium.org/398393003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@284479 0039d316-1c4b-4281-b951-d872f2087c98

ui/events/event.cc

@@ -327,23 +327,46 @@ bool MouseEvent::IsRepeatedClickEvent(
 int MouseEvent::GetRepeatCount(const MouseEvent& event) {
   int click_count = 1;
   if (last_click_event_) {
-    if (event.type() == ui::ET_MOUSE_RELEASED)
-      return last_click_event_->GetClickCount();
-    if (IsX11SendEventTrue(event.native_event()))
+    if (event.type() == ui::ET_MOUSE_RELEASED) {
+      if (event.changed_button_flags() ==
+              last_click_event_->changed_button_flags()) {
+        last_click_complete_ = true;
+        return last_click_event_->GetClickCount();
+      } else {
+        // If last_click_event_ has changed since this button was pressed
+        // return a click count of 1.
+        return click_count;
+      }
+    }
+    if (event.time_stamp() != last_click_event_->time_stamp())
+      last_click_complete_ = true;
+    if (!last_click_complete_ ||
+        IsX11SendEventTrue(event.native_event())) {
       click_count = last_click_event_->GetClickCount();
-    else if (IsRepeatedClickEvent(*last_click_event_, event))
+    } else if (IsRepeatedClickEvent(*last_click_event_, event)) {
       click_count = last_click_event_->GetClickCount() + 1;
+    }
     delete last_click_event_;
   }
   last_click_event_ = new MouseEvent(event);
+  last_click_complete_ = false;
   if (click_count > 3)
     click_count = 3;
   last_click_event_->SetClickCount(click_count);
   return click_count;
 }
 
+void MouseEvent::ResetLastClickForTest() {
+  if (last_click_event_) {
+    delete last_click_event_;
+    last_click_event_ = NULL;
+    last_click_complete_ = false;
+  }
+}
+
 // static
 MouseEvent* MouseEvent::last_click_event_ = NULL;
+bool MouseEvent::last_click_complete_ = false;
 
 int MouseEvent::GetClickCount() const {
   if (type() != ET_MOUSE_PRESSED && type() != ET_MOUSE_RELEASED)

ui/events/event.h

@@ -8,6 +8,7 @@
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/event_types.h"
+#include "base/gtest_prod_util.h"
 #include "base/logging.h"
 #include "base/time/time.h"
 #include "ui/events/event_constants.h"
@@ -402,14 +403,25 @@ class EVENTS_EXPORT MouseEvent : public LocatedEvent {
   void set_changed_button_flags(int flags) { changed_button_flags_ = flags; }
 
  private:
+  FRIEND_TEST_ALL_PREFIXES(EventTest, DoubleClickRequiresRelease);
+  FRIEND_TEST_ALL_PREFIXES(EventTest, SingleClickRightLeft);
+
   // Returns the repeat count based on the previous mouse click, if it is
   // recent enough and within a small enough distance.
   static int GetRepeatCount(const MouseEvent& click_event);
 
+  // Resets the last_click_event_ for unit tests.
+  static void ResetLastClickForTest();
+
   // See description above getter for details.
   int changed_button_flags_;
 
   static MouseEvent* last_click_event_;
+
+  // We can create a MouseEvent for a native event more than once. We set this
+  // to true when the next event either has a different timestamp or we see a
+  // release signalling that the press (click) event was completed.
+  static bool last_click_complete_;
 };
 
 class ScrollEvent;

ui/events/event_unittest.cc

@@ -98,6 +98,68 @@ TEST(EventTest, RepeatedClick) {
   EXPECT_FALSE(MouseEvent::IsRepeatedClickEvent(mouse_ev1, mouse_ev2));
 }
 
+// Tests that an event only increases the click count and gets marked as a
+// double click if a release event was seen for the previous click. This
+// prevents the same PRESSED event from being processed twice:
+// http://crbug.com/389162
+TEST(EventTest, DoubleClickRequiresRelease) {
+  const gfx::Point origin1(0, 0);
+  const gfx::Point origin2(100, 0);
+  scoped_ptr<MouseEvent> ev;
+  base::TimeDelta start = base::TimeDelta::FromMilliseconds(0);
+
+  ev.reset(new MouseEvent(ET_MOUSE_PRESSED, origin1, origin1, 0, 0));
+  ev->set_time_stamp(start);
+  EXPECT_EQ(1, MouseEvent::GetRepeatCount(*ev));
+  ev.reset(new MouseEvent(ET_MOUSE_PRESSED, origin1, origin1, 0, 0));
+  ev->set_time_stamp(start);
+  EXPECT_EQ(1, MouseEvent::GetRepeatCount(*ev));
+
+  ev.reset(new MouseEvent(ET_MOUSE_PRESSED, origin2, origin2, 0, 0));
+  ev->set_time_stamp(start);
+  EXPECT_EQ(1, MouseEvent::GetRepeatCount(*ev));
+  ev.reset(new MouseEvent(ET_MOUSE_RELEASED, origin2, origin2, 0, 0));
+  ev->set_time_stamp(start);
+  EXPECT_EQ(1, MouseEvent::GetRepeatCount(*ev));
+  ev.reset(new MouseEvent(ET_MOUSE_PRESSED, origin2, origin2, 0, 0));
+  ev->set_time_stamp(start);
+  EXPECT_EQ(2, MouseEvent::GetRepeatCount(*ev));
+  ev.reset(new MouseEvent(ET_MOUSE_RELEASED, origin2, origin2, 0, 0));
+  ev->set_time_stamp(start);
+  EXPECT_EQ(2, MouseEvent::GetRepeatCount(*ev));
+  MouseEvent::ResetLastClickForTest();
+}
+
+// Tests that clicking right and then left clicking does not generate a double
+// click.
+TEST(EventTest, SingleClickRightLeft) {
+  const gfx::Point origin(0, 0);
+  scoped_ptr<MouseEvent> ev;
+  base::TimeDelta start = base::TimeDelta::FromMilliseconds(0);
+
+  ev.reset(new MouseEvent(ET_MOUSE_PRESSED, origin, origin,
+                          ui::EF_RIGHT_MOUSE_BUTTON,
+                          ui::EF_RIGHT_MOUSE_BUTTON));
+  ev->set_time_stamp(start);
+  EXPECT_EQ(1, MouseEvent::GetRepeatCount(*ev));
+  ev.reset(new MouseEvent(ET_MOUSE_PRESSED, origin, origin,
+                          ui::EF_LEFT_MOUSE_BUTTON,
+                          ui::EF_LEFT_MOUSE_BUTTON));
+  ev->set_time_stamp(start);
+  EXPECT_EQ(1, MouseEvent::GetRepeatCount(*ev));
+  ev.reset(new MouseEvent(ET_MOUSE_RELEASED, origin, origin,
+                          ui::EF_LEFT_MOUSE_BUTTON,
+                          ui::EF_LEFT_MOUSE_BUTTON));
+  ev->set_time_stamp(start);
+  EXPECT_EQ(1, MouseEvent::GetRepeatCount(*ev));
+  ev.reset(new MouseEvent(ET_MOUSE_PRESSED, origin, origin,
+                          ui::EF_LEFT_MOUSE_BUTTON,
+                          ui::EF_LEFT_MOUSE_BUTTON));
+  ev->set_time_stamp(start);
+  EXPECT_EQ(2, MouseEvent::GetRepeatCount(*ev));
+  MouseEvent::ResetLastClickForTest();
+}
+
 TEST(EventTest, KeyEvent) {
   static const struct {
     KeyboardCode key_code;