gecko-dev/layout/base/SelectionCarets.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=2 sw=2 et tw=78: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef SelectionCarets_h__
#define SelectionCarets_h__
#include "nsIScrollObserver.h"
#include "nsISelectionListener.h"
#include "nsWeakPtr.h"
#include "nsWeakReference.h"
#include "Units.h"
#include "mozilla/EventForwards.h"
class nsCanvasFrame;
class nsIDocument;
class nsIFrame;
class nsIPresShell;
class nsITimer;
class nsIWidget;
class nsPresContext;
namespace mozilla {
/**
* The SelectionCarets draw a pair of carets when the selection is not
* collapsed, one at each end of the selection.
* SelectionCarets also handle visibility, dragging caret and selecting word
* when long tap event fired.
*
* The DOM structure is 2 div elements for showing start and end caret.
*
* Here is an explanation of the html class names:
* .moz-selectioncaret-left: Indicates start DIV.
* .moz-selectioncaret-right: Indicates end DIV.
* .hidden: This class name is set by SetVisibility,
* SetStartFrameVisibility and SetEndFrameVisibility. Element
* with this class name become hidden.
* .tilt: This class name is set by SetTilted. According to the
* UX spec, when selection contains only one characters, the image of
* caret becomes tilt.
*/
class SelectionCarets MOZ_FINAL : public nsISelectionListener,
public nsIScrollObserver,
public nsSupportsWeakReference
{
public:
/**
* Indicate which part of caret we are dragging at.
*/
enum DragMode {
NONE,
START_FRAME,
END_FRAME
};
explicit SelectionCarets(nsIPresShell *aPresShell);
virtual ~SelectionCarets();
NS_DECL_ISUPPORTS
NS_DECL_NSISELECTIONLISTENER
// nsIScrollObserver
virtual void ScrollPositionChanged() MOZ_OVERRIDE;
void Terminate()
{
mPresShell = nullptr;
}
nsEventStatus HandleEvent(WidgetEvent* aEvent);
/**
* Set visibility for selection caret.
*/
void SetVisibility(bool aVisible);
bool GetVisibility() const
{
return mVisible;
}
/**
* Get from pref "selectioncaret.inflatesize.threshold". This will inflate size of
* caret frame when we checking if user click on caret or not. In app units.
*/
static int32_t SelectionCaretsInflateSize()
{
return sSelectionCaretsInflateSize;
}
private:
SelectionCarets() MOZ_DELETE;
/**
* Update selection caret position base on current selection range.
*/
void UpdateSelectionCarets();
/**
* Select word base on current position, only active when element
* is focused. Triggered by long tap event.
*/
nsresult SelectWord();
/**
* Move selection base on current touch/mouse point
*/
nsEventStatus DragSelection(const nsPoint &movePoint);
/**
* Get the vertical center position of selection caret relative to canvas
* frame.
*/
nscoord GetCaretYCenterPosition();
/**
* Simulate mouse down state when we change the selection range.
* Hence, the selection change event will fire normally.
*/
void SetMouseDownState(bool aState);
void SetSelectionDirection(bool aForward);
/**
* Move start frame of selection caret to given position.
* In app units.
*/
void SetStartFramePos(const nsPoint& aPosition);
/**
* Move end frame of selection caret to given position.
* In app units.
*/
void SetEndFramePos(const nsPoint& aPosition);
/**
* Get rect of selection caret's start frame relative
* to document's canvas frame, in app units.
*/
nsRect GetStartFrameRect();
/**
* Get rect of selection caret's end frame relative
* to document's canvas frame, in app units.
*/
nsRect GetEndFrameRect();
/**
* Set visibility for start part of selection caret, this function
* only affects css property of start frame. So it doesn't change
* mVisible member. When caret overflows element's box we'll hide
* it by calling this function.
*/
void SetStartFrameVisibility(bool aVisible);
/**
* Same as above function but for end frame of selection caret.
*/
void SetEndFrameVisibility(bool aVisible);
/**
* Set tilt class name to start and end frame of selection caret.
*/
void SetTilted(bool aIsTilt);
// Utility function
nsIFrame* GetCaretFocusFrame();
bool GetCaretVisible();
nsISelection* GetSelection();
/**
* Detecting long tap using timer
*/
void LaunchLongTapDetector();
void CancelLongTapDetector();
static void FireLongTap(nsITimer* aTimer, void* aSelectionCarets);
void LaunchScrollEndDetector();
static void FireScrollEnd(nsITimer* aTimer, void* aSelectionCarets);
nsIPresShell* mPresShell;
// This timer is used for detecting long tap fire. If content process
// has APZC, we'll use APZC for long tap detecting. Otherwise, we use this
// timer to detect long tap.
nsCOMPtr<nsITimer> mLongTapDetectorTimer;
// This timer is used for detecting scroll end. We don't have
// scroll end event now, so we will fire this event with a
// const time when we scroll. So when timer triggers, we treat it
// as scroll end event.
nsCOMPtr<nsITimer> mScrollEndDetectorTimer;
// When touch or mouse down, we save the position for detecting
// drag distance
nsPoint mDownPoint;
// For filter multitouch event
int32_t mActiveTouchId;
nscoord mCaretCenterToDownPointOffsetY;
DragMode mDragMode;
bool mVisible;
bool mStartCaretVisible;
bool mEndCaretVisible;
// Preference
static int32_t sSelectionCaretsInflateSize;
};
} // namespace mozilla
#endif //SelectionCarets_h__