Keep the size button pressed when the user hovers the snap left or snap right button

ash/wm/caption_buttons/alternate_frame_size_button.cc

 // Copyright 2013 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 "ash/wm/caption_buttons/alternate_frame_size_button.h"
 
 #include "ash/metrics/user_metrics_recorder.h"
 #include "ash/screen_util.h"
 #include "ash/shell.h"
 #include "ash/touch/touch_uma.h"
 #include "ash/wm/window_state.h"
 #include "ash/wm/workspace/phantom_window_controller.h"
 #include "ash/wm/workspace/snap_sizer.h"
 #include "ui/gfx/vector2d.h"
 #include "ui/views/widget/widget.h"
 
 namespace {
 
 // The default delay between the user pressing the size button and the buttons
 // adjacent to the size button morphing into buttons for snapping left and
 // right.
 const int kSetButtonsToSnapModeDelayMs = 150;
 
-// The amount that a user can overshoot the snap left / snap right button and
-// keep the snap left / snap right button pressed.
-const int kPressedHitBoundsExpandX = 200;
-const int kPressedHitBoundsExpandY = 50;
+// The amount that a user can overshoot one of the caption buttons while in
+// "snap mode" and keep the button hovered/pressed.
+const int kMaxOvershootX = 200;
+const int kMaxOvershootY = 50;
+
+// Returns true if a mouse drag while in "snap mode" at |location_in_screen|
+// would hover/press |button| or keep it hovered/pressed.
+bool HitTestButton(const ash::FrameCaptionButton* button,
+                   const gfx::Point& location_in_screen) {
+  gfx::Rect expanded_bounds_in_screen = button->GetBoundsInScreen();
+  if (button->state() == views::Button::STATE_HOVERED ||
+      button->state() == views::Button::STATE_PRESSED) {
+    expanded_bounds_in_screen.Inset(-kMaxOvershootX, -kMaxOvershootY);
+  }
+  return expanded_bounds_in_screen.Contains(location_in_screen);
+}
 
 }  // namespace
 
 namespace ash {
 
 AlternateFrameSizeButton::AlternateFrameSizeButton(
     views::ButtonListener* listener,
     views::Widget* frame,
     AlternateFrameSizeButtonDelegate* delegate)
     : FrameCaptionButton(listener, CAPTION_BUTTON_ICON_MAXIMIZE_RESTORE),
@@ skipping 14 matching lines @@
   if (IsTriggerableEvent(event) &&
       !in_snap_mode_ &&
       delegate_->IsMinimizeButtonVisible()) {
     StartSetButtonsToSnapModeTimer(event);
   }
   FrameCaptionButton::OnMousePressed(event);
   return true;
 }
 
 bool AlternateFrameSizeButton::OnMouseDragged(const ui::MouseEvent& event) {
-  UpdatePressedButton(event);
-  FrameCaptionButton::OnMouseDragged(event);
+  UpdateSnapType(event);
+  // By default a FrameCaptionButton reverts to STATE_NORMAL once the mouse
+  // leaves its bounds. Skip FrameCaptionButton's handling when
+  // |in_snap_mode_| == true because we want different behavior.
+  if (!in_snap_mode_)
+    FrameCaptionButton::OnMouseDragged(event);
   return true;
 }
 
 void AlternateFrameSizeButton::OnMouseReleased(const ui::MouseEvent& event) {
   if (!IsTriggerableEvent(event) || !CommitSnap(event))
     FrameCaptionButton::OnMouseReleased(event);
 }
 
 void AlternateFrameSizeButton::OnMouseCaptureLost() {
   SetButtonsToNormalMode(AlternateFrameSizeButtonDelegate::ANIMATE_YES);
   FrameCaptionButton::OnMouseCaptureLost();
 }
 
+void AlternateFrameSizeButton::OnMouseMoved(const ui::MouseEvent& event) {
+  // Ignore any synthetic mouse moves during a drag.
+  if (!in_snap_mode_)
+    FrameCaptionButton::OnMouseMoved(event);
+}
+
 void AlternateFrameSizeButton::OnGestureEvent(ui::GestureEvent* event) {
   if (event->details().touch_points() > 1) {
     SetButtonsToNormalMode(AlternateFrameSizeButtonDelegate::ANIMATE_YES);
     return;
   }
 
   if (event->type() == ui::ET_GESTURE_TAP_DOWN) {
     StartSetButtonsToSnapModeTimer(*event);
     // Go through FrameCaptionButton's handling so that the button gets pressed.
     FrameCaptionButton::OnGestureEvent(event);
     return;
   }
 
   if (event->type() == ui::ET_GESTURE_SCROLL_BEGIN ||
       event->type() == ui::ET_GESTURE_SCROLL_UPDATE) {
-    UpdatePressedButton(*event);
+    UpdateSnapType(*event);
     event->SetHandled();
     return;
   }
 
   if (event->type() == ui::ET_GESTURE_TAP ||
       event->type() == ui::ET_GESTURE_SCROLL_END ||
       event->type() == ui::ET_SCROLL_FLING_START ||
       event->type() == ui::ET_GESTURE_END) {
     if (CommitSnap(*event)) {
       if (event->type() == ui::ET_GESTURE_TAP) {
@@ skipping 24 matching lines @@
 
 void AlternateFrameSizeButton::SetButtonsToSnapMode() {
   if (in_snap_mode_)
     return;
   in_snap_mode_ = true;
   delegate_->SetButtonIcons(CAPTION_BUTTON_ICON_LEFT_SNAPPED,
                             CAPTION_BUTTON_ICON_RIGHT_SNAPPED,
                             AlternateFrameSizeButtonDelegate::ANIMATE_YES);
 }
 
-void AlternateFrameSizeButton::UpdatePressedButton(
-    const ui::LocatedEvent& event) {
+void AlternateFrameSizeButton::UpdateSnapType(const ui::LocatedEvent& event) {
   if (!in_snap_mode_) {
     // Set the buttons adjacent to the size button to snap left and right early
     // if the user drags past the drag threshold.
     // |set_buttons_to_snap_mode_timer_| is checked to avoid entering the snap
     // mode as a result of an unsupported drag type (e.g. only the right mouse
     // button is pressed).
     gfx::Vector2d delta(
         event.location() - set_buttons_to_snap_mode_timer_event_location_);
     if (!set_buttons_to_snap_mode_timer_.IsRunning() ||
         !views::View::ExceededDragThreshold(delta)) {
       return;
     }
     SetButtonsToSnapMode();
   }
 
   gfx::Point event_location_in_screen(event.location());
   views::View::ConvertPointToScreen(this, &event_location_in_screen);
+  const FrameCaptionButton* to_hover =
+      GetButtonToHover(event_location_in_screen);
+  bool press_size_button =
+      to_hover || HitTestButton(this, event_location_in_screen);
+  delegate_->SetHoveredAndPressedButtons(
+      to_hover, press_size_button ? this : NULL);
 
-  gfx::Insets pressed_button_hittest_insets(-kPressedHitBoundsExpandY,
-                                            -kPressedHitBoundsExpandX,
-                                            -kPressedHitBoundsExpandY,
-                                            -kPressedHitBoundsExpandX);
-  const FrameCaptionButton* pressed_button = delegate_->PressButtonAt(
-      event_location_in_screen, pressed_button_hittest_insets);
   snap_type_ = SNAP_NONE;
-  if (pressed_button) {
-    switch (pressed_button->icon()) {
+  if (to_hover) {
+    switch (to_hover->icon()) {
       case CAPTION_BUTTON_ICON_LEFT_SNAPPED:
         snap_type_ = SNAP_LEFT;
         break;
       case CAPTION_BUTTON_ICON_RIGHT_SNAPPED:
         snap_type_ = SNAP_RIGHT;
         break;
       case CAPTION_BUTTON_ICON_MAXIMIZE_RESTORE:
-        // snap_type_ = SNAP_NONE
-        break;
       case CAPTION_BUTTON_ICON_MINIMIZE:
       case CAPTION_BUTTON_ICON_CLOSE:
         NOTREACHED();
         break;
     }
   }
 
   if (snap_type_ == SNAP_LEFT || snap_type_ == SNAP_RIGHT) {
     if (!phantom_window_controller_.get()) {
       phantom_window_controller_.reset(
           new internal::PhantomWindowController(frame_->GetNativeWindow()));
     }
 
     using internal::SnapSizer;
     SnapSizer snap_sizer(wm::GetWindowState(frame_->GetNativeWindow()),
                          gfx::Point(),
                          snap_type_ == SNAP_LEFT ?
                              SnapSizer::LEFT_EDGE : SnapSizer::RIGHT_EDGE,
                          SnapSizer::OTHER_INPUT);
     phantom_window_controller_->Show(ScreenUtil::ConvertRectToScreen(
           frame_->GetNativeView()->parent(),
           snap_sizer.target_bounds()));
   } else {
     phantom_window_controller_.reset();
   }
 }
 
+const FrameCaptionButton* AlternateFrameSizeButton::GetButtonToHover(
+    const gfx::Point& event_location_in_screen) const {
+  const FrameCaptionButton* closest_button = delegate_->GetButtonClosestTo(
+      event_location_in_screen);
+  if ((closest_button->icon() == CAPTION_BUTTON_ICON_LEFT_SNAPPED ||
+       closest_button->icon() == CAPTION_BUTTON_ICON_RIGHT_SNAPPED) &&
+      HitTestButton(closest_button, event_location_in_screen)) {
+    return closest_button;
+  }
+  return NULL;
+}
+
 bool AlternateFrameSizeButton::CommitSnap(const ui::LocatedEvent& event) {
   // The position of |event| may be different than the position of the previous
   // event.
-  UpdatePressedButton(event);
+  UpdateSnapType(event);
 
   if (in_snap_mode_ &&
       (snap_type_ == SNAP_LEFT || snap_type_ == SNAP_RIGHT)) {
     using internal::SnapSizer;
     SnapSizer::SnapWindow(ash::wm::GetWindowState(frame_->GetNativeWindow()),
                           snap_type_ == SNAP_LEFT ?
                               SnapSizer::LEFT_EDGE : SnapSizer::RIGHT_EDGE);
     ash::Shell::GetInstance()->metrics()->RecordUserMetricsAction(
         snap_type_ == SNAP_LEFT ?
             ash::UMA_WINDOW_MAXIMIZE_BUTTON_MAXIMIZE_LEFT :
             ash::UMA_WINDOW_MAXIMIZE_BUTTON_MAXIMIZE_RIGHT);
     SetButtonsToNormalMode(AlternateFrameSizeButtonDelegate::ANIMATE_NO);
     return true;
   }
   SetButtonsToNormalMode(AlternateFrameSizeButtonDelegate::ANIMATE_YES);
   return false;
 }
 
 void AlternateFrameSizeButton::SetButtonsToNormalMode(
     AlternateFrameSizeButtonDelegate::Animate animate) {
   in_snap_mode_ = false;
   snap_type_ = SNAP_NONE;
   set_buttons_to_snap_mode_timer_.Stop();
   delegate_->SetButtonsToNormal(animate);
   phantom_window_controller_.reset();
 }
 
 }  // namespace ash