Make the cursor have separate mode for disabled mouse events and invisible.

ash/wm/cursor_manager.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 "ash/wm/cursor_manager.h"
 
 #include "ash/shell.h"
 #include "ash/wm/image_cursors.h"
+#include "base/basictypes.h"
 #include "base/logging.h"
+#include "ui/aura/env.h"
 #include "ui/aura/root_window.h"
 #include "ui/base/cursor/cursor.h"
 
 namespace  {
 
+// The coordinate of the cursor used when the cursor is disabled.
+const int kDisabledCursorLocationX = -10000;
+const int kDisabledCursorLocationY = -10000;
+
 void SetCursorOnAllRootWindows(gfx::NativeCursor cursor) {
   ash::Shell::RootWindowList root_windows =
       ash::Shell::GetInstance()->GetAllRootWindows();
   for (ash::Shell::RootWindowList::iterator iter = root_windows.begin();
        iter != root_windows.end(); ++iter)
     (*iter)->SetCursor(cursor);
 }
 
-void NotifyCursorVisibilityChange(bool visible) {
+void NotifyCursorEnableStateChange(bool visible) {
   ash::Shell::RootWindowList root_windows =
       ash::Shell::GetInstance()->GetAllRootWindows();
   for (ash::Shell::RootWindowList::iterator iter = root_windows.begin();
        iter != root_windows.end(); ++iter)
-    (*iter)->OnCursorVisibilityChanged(visible);
+    (*iter)->OnCursorEnableStateChanged(visible);
 }
 
 }  // namespace
 
 namespace ash {
+namespace internal {
+
+// Represents the cursor state which is composed of cursor type, visibility, and
+// enabled state. When the cursor is disabled, the cursor is always invisible.
+// In other words, the cursor cannot be disabled and visible at the same time.
+class CursorState {
+ public:
+  explicit CursorState(gfx::NativeCursor cursor)
+      : cursor_(cursor),
+        visible_(true),
+        enabled_(true),
+        visible_on_enabled_(true) {
+  }
+
+  gfx::NativeCursor cursor() const { return cursor_; }
+  void set_cursor(gfx::NativeCursor cursor) { cursor_ = cursor; }
+
+  bool visible() const { return visible_; }
+  void SetVisible(bool visible) {
+    if (enabled_)
+      visible_ = visible;
+    // Ignores the call when the cursor is disabled.
+  }
+
+  bool enabled() const { return enabled_; }
+  void SetEnabled(bool enabled) {
+    enabled_ = enabled;
+
+    // Restores the visibility when the cursor is enabled.
+    if (enabled) {
+      visible_ = visible_on_enabled_;
+    } else {
+      visible_on_enabled_ = visible_;
+      visible_ = false;
+    }
+  }
+
+ private:
+  gfx::NativeCursor cursor_;
+  bool visible_;
+  bool enabled_;
+
+  // The visibility to set when the cursor is enabled.
+  bool visible_on_enabled_;
+
+  DISALLOW_COPY_AND_ASSIGN(CursorState);
+};
+
+}  // namespace internal
 
 CursorManager::CursorManager()
     : cursor_lock_count_(0),
-      did_cursor_change_(false),
-      cursor_to_set_on_unlock_(0),
-      did_visibility_change_(false),
-      show_on_unlock_(true),
       cursor_visible_(true),
+      cursor_enabled_(true),
       current_cursor_(ui::kCursorNone),
+      state_on_unlock_(new internal::CursorState(ui::kCursorNone)),
       image_cursors_(new ImageCursors) {
 }
 
 CursorManager::~CursorManager() {
 }
 
 void CursorManager::SetCursor(gfx::NativeCursor cursor) {
-  if (cursor_lock_count_ == 0) {
-    SetCursorInternal(cursor);
-  } else {
-    cursor_to_set_on_unlock_ = cursor;
-    did_cursor_change_ = true;
-  }
+  state_on_unlock_->set_cursor(cursor);
+  if (cursor_lock_count_ == 0)
+    SetCursorInternal(state_on_unlock_->cursor());
 }
 
 void CursorManager::ShowCursor(bool show) {
-  if (cursor_lock_count_ == 0) {
-    ShowCursorInternal(show);
-  } else {
-    show_on_unlock_ = show;
-    did_visibility_change_ = true;
-  }
+  state_on_unlock_->SetVisible(show);
+  if (cursor_lock_count_ == 0)
+    ShowCursorInternal(state_on_unlock_->visible());
 }
 
 bool CursorManager::IsCursorVisible() const {
   return cursor_visible_;
 }
 
+void CursorManager::EnableCursor(bool enabled) {
+  state_on_unlock_->SetEnabled(enabled);
+  if (cursor_lock_count_ == 0)
+    EnableCursorInternal(state_on_unlock_->enabled());
+}
+
 void CursorManager::SetDeviceScaleFactor(float device_scale_factor) {
   if (image_cursors_->SetDeviceScaleFactor(device_scale_factor))
     SetCursorInternal(current_cursor_);
 }
 
 void CursorManager::LockCursor() {
   cursor_lock_count_++;
 }
 
 void CursorManager::UnlockCursor() {
   cursor_lock_count_--;
   DCHECK_GE(cursor_lock_count_, 0);
   if (cursor_lock_count_ > 0)
     return;
 
-  if (did_cursor_change_)
-    SetCursorInternal(cursor_to_set_on_unlock_);
-  did_cursor_change_ = false;
-  cursor_to_set_on_unlock_ = gfx::kNullCursor;
+  if (current_cursor_ != state_on_unlock_->cursor())
+    SetCursorInternal(state_on_unlock_->cursor());
 
-  if (did_visibility_change_)
-    ShowCursorInternal(show_on_unlock_);
-  did_visibility_change_ = false;
+  if (cursor_enabled_ != state_on_unlock_->enabled())
+    EnableCursorInternal(state_on_unlock_->enabled());
+
+  if (cursor_visible_ != state_on_unlock_->visible())
+    ShowCursorInternal(state_on_unlock_->visible());

[oshima, 2012/12/06 18:55:46]

It'd be better to have "current_state_", and
"state_on_unlock_", and then do

if (!current_state_.Equals(state_on_unlock))
  UpdateCursorState(state_on_unlock)

?

You can consolidate SetCursorInternal/ShowCursorInternal and
EnableCursorInternal, and ShowCursor/EnableCursor can use the same
UpdateCursorState. What do you think?

[mazda, 2012/12/07 20:50:51]

That's a good idea to have current_state_ and I changed it that way. But I
cannot come up with a good way to consolidate these functions without making the
code more complicated because SetCursorInternal is used from ShowCursorInternal,
and ShowCursorInternal is used from EnableCursorInternal.

 }
 
 void CursorManager::SetCursorInternal(gfx::NativeCursor cursor) {
   current_cursor_ = cursor;
   image_cursors_->SetPlatformCursor(&current_cursor_);
   current_cursor_.set_device_scale_factor(
       image_cursors_->GetDeviceScaleFactor());
 
   if (cursor_visible_)
     SetCursorOnAllRootWindows(current_cursor_);
 }
 
 void CursorManager::ShowCursorInternal(bool show) {
   if (cursor_visible_ == show)
     return;
 
   cursor_visible_ = show;
 
   if (show) {
     SetCursorInternal(current_cursor_);
   } else {
     gfx::NativeCursor invisible_cursor(ui::kCursorNone);
     image_cursors_->SetPlatformCursor(&invisible_cursor);
     SetCursorOnAllRootWindows(invisible_cursor);
   }
-
-  NotifyCursorVisibilityChange(show);
 }
 
+void CursorManager::EnableCursorInternal(bool enabled) {
+  if (cursor_enabled_ == enabled)
+    return;
+
+  cursor_enabled_ = enabled;
+
+  if (enabled) {
+    aura::Env::GetInstance()->set_last_mouse_location(
+        disabled_cursor_location_);
+  } else {
+    disabled_cursor_location_ = aura::Env::GetInstance()->last_mouse_location();
+    aura::Env::GetInstance()->set_last_mouse_location(
+        gfx::Point(kDisabledCursorLocationX, kDisabledCursorLocationY));
+  }
+  ShowCursorInternal(state_on_unlock_->visible());
+  NotifyCursorEnableStateChange(enabled);
+}
+
+
 }  // namespace ash