ui/events/event_utils.h

   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_EVENTS_EVENT_UTILS_H_
   6 #define UI_EVENTS_EVENT_UTILS_H_
   7
   8 #include "base/event_types.h"
   9 #include "ui/events/event_constants.h"
  10 #include "ui/events/keycodes/keyboard_codes.h"
  11 #include "ui/gfx/native_widget_types.h"
  12 #include "ui/events/events_export.h"
  13
  14 #if defined(OS_WIN)
  15 #include <windows.h>
  16 #endif
  17
  18 namespace gfx {
  19 class Point;
  20 class Vector2d;
  21 }
  22
  23 namespace base {
  24 class TimeDelta;
  25 }
  26
  27 namespace ui {
  28
  29 class Event;
  30
  31 // Updates the list of devices for cached properties.
  32 EVENTS_EXPORT void UpdateDeviceList();
  33
  34 // Get the EventType from a native event.
  35 EVENTS_EXPORT EventType EventTypeFromNative(
  36     const base::NativeEvent& native_event);
  37
  38 // Get the EventFlags from a native event.
  39 EVENTS_EXPORT int EventFlagsFromNative(const base::NativeEvent& native_event);
  40
  41 // Get the timestamp from a native event.
  42 EVENTS_EXPORT base::TimeDelta EventTimeFromNative(
  43     const base::NativeEvent& native_event);
  44
  45 // Create a timestamp based on the current time.
  46 EVENTS_EXPORT base::TimeDelta EventTimeForNow();
  47
  48 // Get the location from a native event.  The coordinate system of the resultant
  49 // |Point| has the origin at top-left of the "root window".  The nature of
  50 // this "root window" and how it maps to platform-specific drawing surfaces is
  51 // defined in ui/aura/root_window.* and ui/aura/root_window_host*.
  52 EVENTS_EXPORT gfx::Point EventLocationFromNative(
  53     const base::NativeEvent& native_event);
  54
  55 // Gets the location in native system coordinate space.
  56 EVENTS_EXPORT gfx::Point EventSystemLocationFromNative(
  57     const base::NativeEvent& native_event);
  58
  59 #if defined(USE_X11)
  60 // Returns the 'real' button for an event. The button reported in slave events
  61 // does not take into account any remapping (e.g. using xmodmap), while the
  62 // button reported in master events do. This is a utility function to always
  63 // return the mapped button.
  64 EVENTS_EXPORT int EventButtonFromNative(const base::NativeEvent& native_event);
  65 #endif
  66
  67 // Returns the KeyboardCode from a native event.
  68 EVENTS_EXPORT KeyboardCode KeyboardCodeFromNative(
  69     const base::NativeEvent& native_event);
  70
  71 // Returns true if the message is a mouse event.
  72 EVENTS_EXPORT bool IsMouseEvent(const base::NativeEvent& native_event);
  73
  74 // Returns the flags of the button that changed during a press/release.
  75 EVENTS_EXPORT int GetChangedMouseButtonFlagsFromNative(
  76     const base::NativeEvent& native_event);
  77
  78 // Gets the mouse wheel offsets from a native event.
  79 EVENTS_EXPORT gfx::Vector2d GetMouseWheelOffset(
  80     const base::NativeEvent& native_event);
  81
  82 // Gets the touch id from a native event.
  83 EVENTS_EXPORT int GetTouchId(const base::NativeEvent& native_event);
  84
  85 // Clear the touch id from bookkeeping if it is a release/cancel event.
  86 EVENTS_EXPORT void ClearTouchIdIfReleased(
  87     const base::NativeEvent& native_event);
  88
  89 // Gets the radius along the X/Y axis from a native event. Default is 1.0.
  90 EVENTS_EXPORT float GetTouchRadiusX(const base::NativeEvent& native_event);
  91 EVENTS_EXPORT float GetTouchRadiusY(const base::NativeEvent& native_event);
  92
  93 // Gets the angle of the major axis away from the X axis. Default is 0.0.
  94 EVENTS_EXPORT float GetTouchAngle(const base::NativeEvent& native_event);
  95
  96 // Gets the force from a native_event. Normalized to be [0, 1]. Default is 0.0.
  97 EVENTS_EXPORT float GetTouchForce(const base::NativeEvent& native_event);
  98
  99 // Gets the fling velocity from a native event. is_cancel is set to true if
 100 // this was a tap down, intended to stop an ongoing fling.
 101 EVENTS_EXPORT bool GetFlingData(const base::NativeEvent& native_event,
 102                             float* vx,
 103                             float* vy,
 104                             float* vx_ordinal,
 105                             float* vy_ordinal,
 106                             bool* is_cancel);
 107
 108 // Returns whether this is a scroll event and optionally gets the amount to be
 109 // scrolled. |x_offset|, |y_offset| and |finger_count| can be NULL.
 110 EVENTS_EXPORT bool GetScrollOffsets(const base::NativeEvent& native_event,
 111                                 float* x_offset,
 112                                 float* y_offset,
 113                                 float* x_offset_ordinal,
 114                                 float* y_offset_ordinal,
 115                                 int* finger_count);
 116
 117 EVENTS_EXPORT bool GetGestureTimes(const base::NativeEvent& native_event,
 118                                double* start_time,
 119                                double* end_time);
 120
 121 // Enable/disable natural scrolling for touchpads.
 122 EVENTS_EXPORT void SetNaturalScroll(bool enabled);
 123
 124 // In natural scrolling enabled for touchpads?
 125 EVENTS_EXPORT bool IsNaturalScrollEnabled();
 126
 127 // Returns whether natural scrolling should be used for touchpad.
 128 EVENTS_EXPORT bool ShouldDefaultToNaturalScroll();
 129
 130 // Was this event generated by a touchpad device?
 131 // The caller is responsible for ensuring that this is a mouse/touchpad event
 132 // before calling this function.
 133 EVENTS_EXPORT bool IsTouchpadEvent(const base::NativeEvent& event);
 134
 135 // Returns true if event is noop.
 136 EVENTS_EXPORT bool IsNoopEvent(const base::NativeEvent& event);
 137
 138 // Creates and returns no-op event.
 139 EVENTS_EXPORT base::NativeEvent CreateNoopEvent();
 140
 141 #if defined(OS_WIN)
 142 EVENTS_EXPORT int GetModifiersFromACCEL(const ACCEL& accel);
 143 EVENTS_EXPORT int GetModifiersFromKeyState();
 144
 145 // Returns true if |message| identifies a mouse event that was generated as the
 146 // result of a touch event.
 147 EVENTS_EXPORT bool IsMouseEventFromTouch(UINT message);
 148 #endif
 149
 150 // Returns true if default post-target handling was canceled for |event| after
 151 // its dispatch to its target.
 152 EVENTS_EXPORT bool EventCanceledDefaultHandling(const Event& event);
 153
 154 // Registers a custom event type.
 155 EVENTS_EXPORT int RegisterCustomEventType();
 156
 157 }  // namespace ui
 158
 159 #endif  // UI_EVENTS_EVENT_UTILS_H_