gecko-dev/layout/base/SelectionCarets.h

277 lines
8.2 KiB
C++

/* -*- 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 "nsIReflowObserver.h"
#include "nsIScrollObserver.h"
#include "nsISelectionListener.h"
#include "nsWeakPtr.h"
#include "nsWeakReference.h"
#include "Units.h"
#include "mozilla/dom/SelectionStateChangedEvent.h"
#include "mozilla/EventForwards.h"
#include "mozilla/WeakPtr.h"
class nsCanvasFrame;
class nsDocShell;
class nsFrameSelection;
class nsIContent;
class nsIDocument;
class nsIFrame;
class nsIPresShell;
class nsITimer;
class nsIWidget;
class nsPresContext;
namespace mozilla {
namespace dom {
class Selection;
}
/**
* 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.
* Each div element has a child div element. That is, each caret consist of
* outer div and inner div. Outer div takes responsibility for detecting two
* carets are overlapping. Inner div is for actual appearance.
*
* 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 carets are overlapping, the image of
* caret becomes tilt.
*/
class SelectionCarets MOZ_FINAL : public nsIReflowObserver,
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);
NS_DECL_ISUPPORTS
NS_DECL_NSIREFLOWOBSERVER
NS_DECL_NSISELECTIONLISTENER
// Notify selection carets about the blur event to hidden itself
void NotifyBlur(bool aIsLeavingDocument);
// nsIScrollObserver
virtual void ScrollPositionChanged() MOZ_OVERRIDE;
// AsyncPanZoom started/stopped callbacks from nsIScrollObserver
virtual void AsyncPanZoomStarted(const mozilla::CSSIntPoint aScrollPos) MOZ_OVERRIDE;
virtual void AsyncPanZoomStopped(const mozilla::CSSIntPoint aScrollPos) MOZ_OVERRIDE;
void Init();
void Terminate();
nsEventStatus HandleEvent(WidgetEvent* aEvent);
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:
virtual ~SelectionCarets();
SelectionCarets() = delete;
/**
* Set visibility for selection caret.
*/
void SetVisibility(bool aVisible);
/**
* Update selection caret position base on current selection range.
*/
void UpdateSelectionCarets();
/**
* Select a word base on current position, which activates only if element is
* selectable. 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 root
* frame.
*/
nscoord GetCaretYCenterPosition();
/**
* Simulate drag state when we change the selection range.
* Hence, the selection change event will fire normally.
*/
void SetSelectionDragState(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);
/**
* Check if aPosition is on the start or end frame of the
* selection caret's inner div element.
*
* @param aPosition should be relative to document's root frame
* in app units
*/
bool IsOnStartFrameInner(const nsPoint& aPosition);
bool IsOnEndFrameInner(const nsPoint& aPosition);
/**
* Get rect of selection caret's outer div element relative
* to document's root frame, in app units.
*/
nsRect GetStartFrameRect();
nsRect GetEndFrameRect();
/**
* Get rect of selection caret's inner div element relative
* to document's root frame, in app units.
*/
nsRect GetStartFrameRectInner();
nsRect GetEndFrameRectInner();
/**
* 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 functions
dom::Selection* GetSelection();
already_AddRefed<nsFrameSelection> GetFrameSelection();
nsIContent* GetFocusedContent();
void DispatchSelectionStateChangedEvent(dom::Selection* aSelection,
dom::SelectionState aState);
void DispatchSelectionStateChangedEvent(dom::Selection* aSelection,
const dom::Sequence<dom::SelectionState>& aStates);
void DispatchCustomEvent(const nsAString& aEvent);
/**
* Detecting long tap using timer
*/
void LaunchLongTapDetector();
void CancelLongTapDetector();
static void FireLongTap(nsITimer* aTimer, void* aSelectionCarets);
void LaunchScrollEndDetector();
void CancelScrollEndDetector();
static void FireScrollEnd(nsITimer* aTimer, void* aSelectionCarets);
nsIPresShell* mPresShell;
WeakPtr<nsDocShell> mDocShell;
// 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;
// The horizontal boundary is defined by the first selected frame which
// determines the start-caret position. When users drag the end-caret up,
// the touch input(pos.y) will be changed to not cross this boundary.
// Otherwise, the selection range changes to one character only
// which causes the bad user experience.
nscoord mDragUpYBoundary;
// The horizontal boundary is defined by the last selected frame which
// determines the end-caret position. When users drag the start-caret down,
// the touch input(pos.y) will be changed to not cross this boundary.
// Otherwise, the selection range changes to one character only
// which causes the bad user experience.
nscoord mDragDownYBoundary;
DragMode mDragMode;
// True if AsyncPanZoom is enabled
bool mAsyncPanZoomEnabled;
// True if AsyncPanZoom is started
bool mInAsyncPanZoomGesture;
bool mEndCaretVisible;
bool mStartCaretVisible;
bool mSelectionVisibleInScrollFrames;
bool mVisible;
// Preference
static int32_t sSelectionCaretsInflateSize;
};
} // namespace mozilla
#endif //SelectionCarets_h__