components/mus/focus_controller.cc

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "components/mus/focus_controller.h"
   6
   7 #include "components/mus/focus_controller_delegate.h"
   8 #include "components/mus/server_view.h"
   9 #include "components/mus/server_view_drawn_tracker.h"
  10
  11 namespace mus {
  12
  13 FocusController::FocusController(FocusControllerDelegate* delegate)
  14     : delegate_(delegate) {}
  15
  16 FocusController::~FocusController() {}
  17
  18 void FocusController::SetFocusedView(ServerView* view) {
  19   if (GetFocusedView() == view)
  20     return;
  21
  22   SetFocusedViewImpl(view, CHANGE_SOURCE_EXPLICIT);
  23 }
  24
  25 ServerView* FocusController::GetFocusedView() {
  26   return drawn_tracker_ ? drawn_tracker_->view() : nullptr;
  27 }
  28
  29 void FocusController::SetFocusedViewImpl(ServerView* view,
  30                                          ChangeSource change_source) {
  31   ServerView* old = GetFocusedView();
  32
  33   DCHECK(!view || view->IsDrawn());
  34
  35   if (view)
  36     drawn_tracker_.reset(new ServerViewDrawnTracker(view, this));
  37   else
  38     drawn_tracker_.reset();
  39
  40   if (change_source == CHANGE_SOURCE_DRAWN_STATE_CHANGED)
  41     delegate_->OnFocusChanged(old, view);
  42 }
  43
  44 void FocusController::OnDrawnStateChanged(ServerView* ancestor,
  45                                           ServerView* view,
  46                                           bool is_drawn) {
  47   DCHECK(!is_drawn);  // We only observe when drawn.
  48   SetFocusedViewImpl(ancestor, CHANGE_SOURCE_DRAWN_STATE_CHANGED);
  49 }
  50
  51 }  // namespace mus