/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ /* vim: set ts=8 sts=2 et sw=2 tw=80: */ /* 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/. */ /* the caret is the text cursor used, e.g., when editing */ #ifndef nsCaret_h__ #define nsCaret_h__ #include "mozilla/MemoryReporting.h" #include "mozilla/SelectionMovementUtils.h" #include "nsCoord.h" #include "nsIFrame.h" #include "nsISelectionListener.h" #include "nsPoint.h" #include "nsRect.h" class nsFrameSelection; class nsIContent; class nsIFrame; class nsINode; class nsITimer; namespace mozilla { class PresShell; enum class CaretAssociationHint; namespace gfx { class DrawTarget; } // namespace gfx } // namespace mozilla //----------------------------------------------------------------------------- class nsCaret final : public nsISelectionListener { typedef mozilla::gfx::DrawTarget DrawTarget; public: nsCaret(); protected: virtual ~nsCaret(); public: NS_DECL_ISUPPORTS using CaretAssociationHint = mozilla::CaretAssociationHint; nsresult Init(mozilla::PresShell*); void Terminate(); void SetSelection(mozilla::dom::Selection*); mozilla::dom::Selection* GetSelection(); /** * Sets whether the caret should only be visible in nodes that are not * user-modify: read-only, or whether it should be visible in all nodes. * * @param aIgnoreUserModify true to have the cursor visible in all nodes, * false to have it visible in all nodes except * those with user-modify: read-only */ void SetIgnoreUserModify(bool aIgnoreUserModify); /** * SetVisible will set the visibility of the caret * @param aVisible true to show the caret, false to hide it */ void SetVisible(bool aVisible); /** * IsVisible will get the visibility of the caret. * It does not take account of blinking or the caret being hidden because * we're in non-editable/disabled content. */ bool IsVisible() const; /** * AddForceHide() increases mHideCount and hide the caret even if * SetVisible(true) has been or will be called. This is useful when the * caller wants to hide caret temporarily and it needs to cancel later. * Especially, in the latter case, it's too difficult to decide if the * caret should be actually visible or not because caret visible state * is set from a lot of event handlers. So, it's very stateful. */ void AddForceHide(); /** * RemoveForceHide() decreases mHideCount if it's over 0. * If the value becomes 0, this may show the caret if SetVisible(true) * has been called. */ void RemoveForceHide(); /** SetCaretReadOnly set the appearance of the caret * @param inMakeReadonly true to show the caret in a 'read only' state, * false to show the caret in normal, editing state */ void SetCaretReadOnly(bool aReadOnly); /** * @param aVisibility true if the caret should be visible even when the * selection is not collapsed. */ void SetVisibilityDuringSelection(bool aVisibility); /** * Set the caret's position explicitly to the specified node and offset * instead of tracking its selection. * Passing null for aNode would set the caret to track its selection again. **/ void SetCaretPosition(nsINode* aNode, int32_t aOffset); /** * Schedule a repaint for the frame where the caret would appear. * Does not check visibility etc. */ void SchedulePaint(); nsIFrame* GetLastPaintedFrame() { return mLastPaintedFrame; } void SetLastPaintedFrame(nsIFrame* aFrame) { mLastPaintedFrame = aFrame; } /** * Returns a frame to paint in, and the bounds of the painted caret * relative to that frame. * The rectangle includes bidi decorations. * Returns null if the caret should not be drawn (including if it's blinked * off). */ nsIFrame* GetPaintGeometry(nsRect* aRect); /** * Same as the overload above, but returns the caret and hook rects * separately, and also computes the color if requested. */ nsIFrame* GetPaintGeometry(nsRect* aCaretRect, nsRect* aHookRect, nscolor* aCaretColor = nullptr); /** * A simple wrapper around GetGeometry. Does not take any caret state into * account other than the current selection. */ nsIFrame* GetGeometry(nsRect* aRect) { return GetGeometry(GetSelection(), aRect); } /** PaintCaret * Actually paint the caret onto the given rendering context. */ void PaintCaret(DrawTarget& aDrawTarget, nsIFrame* aForFrame, const nsPoint& aOffset); // nsISelectionListener interface NS_DECL_NSISELECTIONLISTENER /** The current caret position. */ struct CaretPosition { nsCOMPtr mContent; int32_t mOffset = 0; CaretAssociationHint mHint{0}; mozilla::intl::BidiEmbeddingLevel mBidiLevel; bool operator==(const CaretPosition& aOther) const { return mContent == aOther.mContent && mOffset == aOther.mOffset && mHint == aOther.mHint && mBidiLevel == aOther.mBidiLevel; } explicit operator bool() const { return !!mContent; } }; static CaretPosition CaretPositionFor(const mozilla::dom::Selection*); /** * Gets the position and size of the caret that would be drawn for * the focus node/offset of aSelection (assuming it would be drawn, * i.e., disregarding blink status). The geometry is stored in aRect, * and we return the frame aRect is relative to. * Only looks at the focus node of aSelection, so you can call it even if * aSelection is not collapsed. * This rect does not include any extra decorations for bidi. * @param aRect must be non-null */ static nsIFrame* GetGeometry(const mozilla::dom::Selection* aSelection, nsRect* aRect); static nsRect GetGeometryForFrame(nsIFrame* aFrame, int32_t aFrameOffset, nscoord* aBidiIndicatorSize); // Get the frame and frame offset based on aPosition. static mozilla::CaretFrameData GetFrameAndOffset( const CaretPosition& aPosition); size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const; protected: static void CaretBlinkCallback(nsITimer* aTimer, void* aClosure); void CheckSelectionLanguageChange(); void CaretVisibilityMaybeChanged(); void ResetBlinking(); void StopBlinking(); struct Metrics { nscoord mBidiIndicatorSize; // width and height of bidi indicator nscoord mCaretWidth; // full caret width including bidi indicator }; static Metrics ComputeMetrics(nsIFrame* aFrame, int32_t aOffset, nscoord aCaretHeight); void ComputeCaretRects(nsIFrame* aFrame, int32_t aFrameOffset, nsRect* aCaretRect, nsRect* aHookRect); // If we're tracking the selection, this updates the caret position and // invalidates paint as needed. void UpdateCaretPositionFromSelectionIfNeeded(); nsWeakPtr mPresShell; mozilla::WeakPtr mDomSelectionWeak; nsCOMPtr mBlinkTimer; CaretPosition mCaretPosition; // The last frame we painted the caret in. WeakFrame mLastPaintedFrame; /** * mBlinkCount is used to control the number of times to blink the caret * before stopping the blink. This is reset each time we reset the * blinking. */ int32_t mBlinkCount = -1; /** * mBlinkRate is the rate of the caret blinking the last time we read it. * It is used as a way to optimize whether we need to reset the blinking * timer. 0 or a negative value means no blinking. */ int32_t mBlinkRate = 0; /** * mHideCount is not 0, it means that somebody doesn't want the caret * to be visible. See AddForceHide() and RemoveForceHide(). */ uint32_t mHideCount = 0; /** * mIsBlinkOn is true when we're in a blink cycle where the caret is on. */ bool mIsBlinkOn = false; /** * mIsVisible is true when SetVisible was last called with 'true'. */ bool mVisible = false; /** * mReadOnly is true when the caret is set to "read only" mode (i.e., * it doesn't blink). */ bool mReadOnly = false; /** * mShowDuringSelection is true when the caret should be shown even when * the selection is not collapsed. */ bool mShowDuringSelection = false; /** * mIgnoreUserModify is true when the caret should be shown even when * it's in non-user-modifiable content. */ bool mIgnoreUserModify = true; /** * If the caret position is fixed, it's been overridden externally and it * will not track the selection. */ bool mFixedCaretPosition = false; /** * If we're currently hiding the caret due to the selection not being * collapsed. Can only be true if mShowDuringSelection is false. */ bool mHiddenDuringSelection = false; }; #endif // nsCaret_h__