Make long press & release to trigger context menu on tab

chrome/browser/ui/views/tabs/tab_strip.cc

 // Copyright (c) 2012 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/views/tabs/tab_strip.h"
 
 #if defined(OS_WIN)
 #include <windowsx.h>
 #endif
 
@@ skipping 569 matching lines @@
       newtab_button_(NULL),
       current_unselected_width_(Tab::GetStandardSize().width()),
       current_selected_width_(Tab::GetStandardSize().width()),
       available_width_for_tabs_(-1),
       in_tab_close_(false),
       animation_container_(new ui::AnimationContainer()),
       ALLOW_THIS_IN_INITIALIZER_LIST(bounds_animator_(this)),
       layout_type_(TAB_STRIP_LAYOUT_SHRINK),
       adjust_layout_(false),
       reset_to_shrink_on_exit_(false),
+      was_dragging_(false),
+      had_gesture_long_press_(false),
       mouse_move_count_(0),
       immersive_style_(false) {
   Init();
 }
 
 TabStrip::~TabStrip() {
   FOR_EACH_OBSERVER(TabStripObserver, observers_,
                     TabStripDeleted(this));
 
   // The animations may reference the tabs. Shut down the animation before we
@@ skipping 893 matching lines @@
 
 void TabStrip::OnGestureEvent(ui::GestureEvent* event) {
   SetResetToShrinkOnExit(false);
   switch (event->type()) {
     case ui::ET_GESTURE_END:
       EndDrag(END_DRAG_COMPLETE);
       if (adjust_layout_) {
         SetLayoutType(TAB_STRIP_LAYOUT_STACKED, true);
         controller_->LayoutTypeMaybeChanged();
       }
+      // If there was long press gesture and no dragging,
+      // show the context menu at finger lift.
+      if (!was_dragging_ && had_gesture_long_press_) {
+        Tab* tab = FindTabForEvent(last_long_press_location_);
+        if (tab) {
+          gfx::Point local_point(last_long_press_location_);
+          ConvertPointToScreen(this, &local_point);
+          ShowContextMenuForTab(tab, local_point);

[sadrul, 2013/03/19 22:17:31]

The finger may have moved a significant distance after the long-press event. I
don't think we should show the context menu in such scenario.

You should should the context menu on GESTURE_LONG_TAP gesture instead. (so you
won't need any of the new states, i.e. was_dragging_, had_gesture_long_press_ or
last_long_press_location)

[Yufeng Shen (Slow to review), 2013/03/19 23:37:38]

If the finger has moved a significant distance, then it would have triggered
ui::ET_GESTURE_SCROLL_UPDATE and marked as dragging I think.
 
The tricky part is that we currently use GESTURE_LONG_PRESS
as switch between dragging and scrolling mode on the tab strip (see issue
161634). So showing context menu after long press but before finger lift would
somehow make the whole thing even more confusing.

+        }
+      }
+      had_gesture_long_press_ = false;
+      was_dragging_ = false;
       break;
 
     case ui::ET_GESTURE_LONG_PRESS:
       if (drag_controller_.get())
         drag_controller_->SetMoveBehavior(TabDragController::REORDER);
+      had_gesture_long_press_ = true;
+      last_long_press_location_ = event->location();
       break;
 
     case ui::ET_GESTURE_SCROLL_UPDATE:
       ContinueDrag(this, *event);
+      was_dragging_ = true;
       break;
 
     case ui::ET_GESTURE_BEGIN:
       EndDrag(END_DRAG_CANCEL);
       break;
 
     default:
       break;
   }
   event->SetHandled();
@@ skipping 964 matching lines @@
 
 int TabStrip::GetStartXForNormalTabs() const {
   int mini_tab_count = GetMiniTabCount();
   if (mini_tab_count == 0)
     return 0;
   return mini_tab_count * (Tab::GetMiniWidth() + tab_h_offset()) +
       kMiniToNonMiniGap;
 }
 
 Tab* TabStrip::FindTabForEvent(const gfx::Point& point) {
-  DCHECK(touch_layout_.get());
-  int active_tab_index = touch_layout_->active_index();
   Tab* tab = NULL;
-  if (active_tab_index != -1) {
-    tab = FindTabForEventFrom(point, active_tab_index, -1);
-    if (!tab)
-      tab = FindTabForEventFrom(point, active_tab_index + 1, 1);
-  } else if (tab_count()) {
-    tab = FindTabForEventFrom(point, 0, 1);
+  if (touch_layout_.get()) {
+    int active_tab_index = touch_layout_->active_index();
+    if (active_tab_index != -1) {
+      tab = FindTabForEventFrom(point, active_tab_index, -1);
+      if (!tab)
+        tab = FindTabForEventFrom(point, active_tab_index + 1, 1);
+    } else if (tab_count()) {
+      tab = FindTabForEventFrom(point, 0, 1);
+    }
+  } else {
+    for (int i = 0; i < tab_count(); ++i) {
+      if (IsPointInTab(tab_at(i), point)) {
+        tab = tab_at(i);
+        break;
+      }
+    }
   }
   return tab;
 }
 
 Tab* TabStrip::FindTabForEventFrom(const gfx::Point& point,
                                    int start,
                                    int delta) {
   // |start| equals tab_count() when there are only pinned tabs.
   if (start == tab_count())
     start += delta;
@@ skipping 78 matching lines @@
   if (!adjust_layout_)
     return false;
 
 #if !defined(OS_CHROMEOS)
   if (ui::GetDisplayLayout() != ui::LAYOUT_TOUCH)
     return false;
 #endif
 
   return true;
 }