gecko-dev/layout/base/nsCaret.h

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/* -*- 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/dom/Selection.h"
#include "nsCoord.h"
#include "nsISelectionListener.h"
#include "nsIWeakReferenceUtils.h"
#include "CaretAssociationHint.h"
#include "nsPoint.h"
#include "nsRect.h"
class nsDisplayListBuilder;
class nsFrameSelection;
class nsIContent;
class nsIFrame;
class nsINode;
class nsITimer;
namespace mozilla {
class PresShell;
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
typedef mozilla::CaretAssociationHint CaretAssociationHint;
nsresult Init(mozilla::PresShell* aPresShell);
void Terminate();
void SetSelection(mozilla::dom::Selection* aDOMSel);
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 inMakeVisible true to show the caret, false to hide it
*/
void SetVisible(bool intMakeVisible);
/** IsVisible will get the visibility of the caret.
* This returns false if the caret is hidden because it was set
* to not be visible, or because the selection is not collapsed, or
* because an open popup is hiding the caret.
* It does not take account of blinking or the caret being hidden
* because we're in non-editable/disabled content.
*/
bool IsVisible(mozilla::dom::Selection* aSelection = nullptr) {
if (!mVisible || mHideCount) {
return false;
}
if (!mShowDuringSelection) {
mozilla::dom::Selection* selection;
if (aSelection) {
selection = aSelection;
} else {
selection = GetSelection();
}
if (!selection || !selection->IsCollapsed()) {
return false;
}
}
if (IsMenuPopupHidingCaret()) {
return false;
}
return true;
}
/**
* 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 inMakeReadonly);
/**
* @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(mozilla::dom::Selection* aSelection = nullptr);
/**
* 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);
/**
* 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
/**
* 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(mozilla::dom::Selection* aSelection,
nsRect* aRect);
static nsIFrame* GetCaretFrameForNodeOffset(
nsFrameSelection* aFrameSelection, nsIContent* aContentNode,
int32_t aOffset, CaretAssociationHint aFrameHint, uint8_t aBidiLevel,
nsIFrame** aReturnUnadjustedFrame, int32_t* aReturnOffset);
static nsRect GetGeometryForFrame(nsIFrame* aFrame, int32_t aFrameOffset,
nscoord* aBidiIndicatorSize);
// Get the frame and frame offset based on the focus node and focus offset
// of aSelection. If aOverrideNode and aOverride are provided, use them
// instead.
// @param aFrameOffset return the frame offset if non-null.
// @param aUnadjustedFrame return the original frame that the selection is
// targeting, without any adjustment for painting.
// @return the frame of the focus node.
static nsIFrame* GetFrameAndOffset(mozilla::dom::Selection* aSelection,
nsINode* aOverrideNode,
int32_t aOverrideOffset,
int32_t* aFrameOffset,
nsIFrame** aUnadjustedFrame = nullptr);
size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
nsIFrame* GetFrame(int32_t* aContentOffset);
void ComputeCaretRects(nsIFrame* aFrame, int32_t aFrameOffset,
nsRect* aCaretRect, nsRect* aHookRect);
protected:
static void CaretBlinkCallback(nsITimer* aTimer, void* aClosure);
void CheckSelectionLanguageChange();
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);
// Returns true if we should not draw the caret because of XUL menu popups.
// The caret should be hidden if:
// 1. An open popup contains the caret, but a menu popup exists before the
// caret-owning popup in the popup list (i.e. a menu is in front of the
// popup with the caret). If the menu itself contains the caret we don't
// hide it.
// 2. A menu popup is open, but there is no caret present in any popup.
// 3. The caret selection is empty.
bool IsMenuPopupHidingCaret();
nsWeakPtr mPresShell;
mozilla::WeakPtr<mozilla::dom::Selection> mDomSelectionWeak;
nsCOMPtr<nsITimer> mBlinkTimer;
/**
* The content to draw the caret at. If null, we use mDomSelectionWeak's
* focus node instead.
*/
nsCOMPtr<nsINode> mOverrideContent;
/**
* The character offset to draw the caret at.
* Ignored if mOverrideContent is null.
*/
int32_t mOverrideOffset;
/**
* 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;
/**
* 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.
*/
uint32_t mBlinkRate;
/**
* mHideCount is not 0, it means that somebody doesn't want the caret
* to be visible. See AddForceHide() and RemoveForceHide().
*/
uint32_t mHideCount;
/**
* mIsBlinkOn is true when we're in a blink cycle where the caret is on.
*/
bool mIsBlinkOn;
/**
* mIsVisible is true when SetVisible was last called with 'true'.
*/
bool mVisible;
/**
* mReadOnly is true when the caret is set to "read only" mode (i.e.,
* it doesn't blink).
*/
bool mReadOnly;
/**
* mShowDuringSelection is true when the caret should be shown even when
* the selection is not collapsed.
*/
bool mShowDuringSelection;
/**
* mIgnoreUserModify is true when the caret should be shown even when
* it's in non-user-modifiable content.
*/
bool mIgnoreUserModify;
};
#endif // nsCaret_h__