/* -*- 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();
/**
* 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 optionally 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();
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<nsINode> 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<mozilla::dom::Selection> mDomSelectionWeak;
nsCOMPtr<nsITimer> 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;
/**
* 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__
