1 // Copyright (c) 2012 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 #ifndef UI_DISPLAY_DISPLAY_OBSERVER_H_ 6 #define UI_DISPLAY_DISPLAY_OBSERVER_H_ 7 8 #include <stdint.h> 9 10 #include "base/observer_list_types.h" 11 #include "ui/display/display_export.h" 12 13 namespace display { 14 class Display; 15 16 // Observers for display configuration changes. 17 class DISPLAY_EXPORT DisplayObserver : public base::CheckedObserver { 18 public: 19 enum DisplayMetric { 20 DISPLAY_METRIC_NONE = 0, 21 DISPLAY_METRIC_BOUNDS = 1 << 0, 22 DISPLAY_METRIC_WORK_AREA = 1 << 1, 23 DISPLAY_METRIC_DEVICE_SCALE_FACTOR = 1 << 2, 24 DISPLAY_METRIC_ROTATION = 1 << 3, 25 DISPLAY_METRIC_PRIMARY = 1 << 4, 26 DISPLAY_METRIC_MIRROR_STATE = 1 << 5, 27 DISPLAY_METRIC_COLOR_SPACE = 1 << 6, 28 }; 29 30 // This may be called before other methods to signal changes are about to 31 // happen. Not all classes that support DisplayObserver call this. 32 virtual void OnWillProcessDisplayChanges(); 33 34 // Called after OnWillProcessDisplayChanges() to indicate display changes have 35 // completed. Not all classes that support DisplayObserver call this. 36 virtual void OnDidProcessDisplayChanges(); 37 38 // Called when |new_display| has been added. 39 virtual void OnDisplayAdded(const Display& new_display); 40 41 // Called when |old_display| has been removed. 42 virtual void OnDisplayRemoved(const Display& old_display); 43 44 // Called when the metrics of a display change. 45 // |changed_metrics| is a bitmask of DisplayMatric types indicating which 46 // metrics have changed. Eg; if mirroring changes (either from true to false, 47 // or false to true), than the DISPLAY_METRIC_MIRROR_STATE bit is set in 48 // changed_metrics. 49 virtual void OnDisplayMetricsChanged(const Display& display, 50 uint32_t changed_metrics); 51 52 // Called when the (platform-specific) workspace ID changes to 53 // |new_workspace|. 54 virtual void OnCurrentWorkspaceChanged(const std::string& new_workspace); 55 56 protected: 57 ~DisplayObserver() override; 58 }; 59 60 } // namespace display 61 62 #endif // UI_DISPLAY_DISPLAY_OBSERVER_H_ 63