gecko-dev/widget/ContentCache.h

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C
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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: sw=2 ts=8 et :
*/
/* 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 mozilla_ContentCache_h
#define mozilla_ContentCache_h
#include <stdint.h>
#include "mozilla/Assertions.h"
#include "mozilla/CheckedInt.h"
#include "mozilla/EventForwards.h"
#include "mozilla/WritingModes.h"
#include "nsIWidget.h"
#include "nsString.h"
#include "nsTArray.h"
#include "Units.h"
namespace mozilla {
class ContentCacheInParent;
/**
* ContentCache stores various information of the child content.
* This class has members which are necessary both in parent process and
* content process.
*/
class ContentCache
{
public:
typedef InfallibleTArray<LayoutDeviceIntRect> RectArray;
typedef widget::IMENotification IMENotification;
ContentCache();
protected:
// Whole text in the target
nsString mText;
struct Selection final
{
// Following values are offset in "flat text".
uint32_t mAnchor;
uint32_t mFocus;
WritingMode mWritingMode;
// Character rects at next character of mAnchor and mFocus.
LayoutDeviceIntRect mAnchorCharRect;
LayoutDeviceIntRect mFocusCharRect;
// Whole rect of selected text. This is empty if the selection is collapsed.
LayoutDeviceIntRect mRect;
Selection()
: mAnchor(UINT32_MAX)
, mFocus(UINT32_MAX)
{
}
void Clear()
{
mAnchor = mFocus = UINT32_MAX;
mWritingMode = WritingMode();
mAnchorCharRect.SetEmpty();
mFocusCharRect.SetEmpty();
mRect.SetEmpty();
}
bool IsValid() const
{
return mAnchor != UINT32_MAX && mFocus != UINT32_MAX;
}
bool Collapsed() const
{
NS_ASSERTION(IsValid(),
"The caller should check if the selection is valid");
return mFocus == mAnchor;
}
bool Reversed() const
{
NS_ASSERTION(IsValid(),
"The caller should check if the selection is valid");
return mFocus < mAnchor;
}
uint32_t StartOffset() const
{
NS_ASSERTION(IsValid(),
"The caller should check if the selection is valid");
return Reversed() ? mFocus : mAnchor;
}
uint32_t EndOffset() const
{
NS_ASSERTION(IsValid(),
"The caller should check if the selection is valid");
return Reversed() ? mAnchor : mFocus;
}
uint32_t Length() const
{
NS_ASSERTION(IsValid(),
"The caller should check if the selection is valid");
return Reversed() ? mAnchor - mFocus : mFocus - mAnchor;
}
} mSelection;
bool IsSelectionValid() const
{
return mSelection.IsValid() && mSelection.EndOffset() <= mText.Length();
}
// Stores first char rect because Yosemite's Japanese IME sometimes tries
// to query it. If there is no text, this is caret rect.
LayoutDeviceIntRect mFirstCharRect;
struct Caret final
{
uint32_t mOffset;
LayoutDeviceIntRect mRect;
Caret()
: mOffset(UINT32_MAX)
{
}
void Clear()
{
mOffset = UINT32_MAX;
mRect.SetEmpty();
}
bool IsValid() const { return mOffset != UINT32_MAX; }
uint32_t Offset() const
{
NS_ASSERTION(IsValid(),
"The caller should check if the caret is valid");
return mOffset;
}
} mCaret;
struct TextRectArray final
{
uint32_t mStart;
RectArray mRects;
TextRectArray()
: mStart(UINT32_MAX)
{
}
void Clear()
{
mStart = UINT32_MAX;
mRects.Clear();
}
bool IsValid() const
{
if (mStart == UINT32_MAX) {
return false;
}
CheckedInt<uint32_t> endOffset =
CheckedInt<uint32_t>(mStart) + mRects.Length();
return endOffset.isValid();
}
uint32_t StartOffset() const
{
NS_ASSERTION(IsValid(),
"The caller should check if the caret is valid");
return mStart;
}
uint32_t EndOffset() const
{
NS_ASSERTION(IsValid(),
"The caller should check if the caret is valid");
if (!IsValid()) {
return UINT32_MAX;
}
return mStart + mRects.Length();
}
bool InRange(uint32_t aOffset) const
{
return IsValid() &&
StartOffset() <= aOffset && aOffset < EndOffset();
}
bool InRange(uint32_t aOffset, uint32_t aLength) const
{
CheckedInt<uint32_t> endOffset =
CheckedInt<uint32_t>(aOffset) + aLength;
if (NS_WARN_IF(!endOffset.isValid())) {
return false;
}
return InRange(aOffset) && aOffset + aLength <= EndOffset();
}
bool IsOverlappingWith(uint32_t aOffset, uint32_t aLength) const
{
if (!IsValid() || aOffset == UINT32_MAX) {
return false;
}
CheckedInt<uint32_t> endOffset =
CheckedInt<uint32_t>(aOffset) + aLength;
if (NS_WARN_IF(!endOffset.isValid())) {
return false;
}
return aOffset <= EndOffset() && endOffset.value() >= mStart;
}
LayoutDeviceIntRect GetRect(uint32_t aOffset) const;
LayoutDeviceIntRect GetUnionRect(uint32_t aOffset, uint32_t aLength) const;
LayoutDeviceIntRect GetUnionRectAsFarAsPossible(uint32_t aOffset,
uint32_t aLength) const;
} mTextRectArray;
LayoutDeviceIntRect mEditorRect;
friend class ContentCacheInParent;
friend struct IPC::ParamTraits<ContentCache>;
};
class ContentCacheInChild final : public ContentCache
{
public:
ContentCacheInChild();
/**
* When IME loses focus, this should be called and making this forget the
* content for reducing footprint.
*/
void Clear();
/**
* Cache*() retrieves the latest content information and store them.
* Be aware, CacheSelection() calls CacheTextRects(), and also CacheText()
* calls CacheSelection(). So, related data is also retrieved automatically.
*/
bool CacheEditorRect(nsIWidget* aWidget,
const IMENotification* aNotification = nullptr);
bool CacheSelection(nsIWidget* aWidget,
const IMENotification* aNotification = nullptr);
bool CacheText(nsIWidget* aWidget,
const IMENotification* aNotification = nullptr);
bool CacheAll(nsIWidget* aWidget,
const IMENotification* aNotification = nullptr);
/**
* SetSelection() modifies selection with specified raw data. And also this
* tries to retrieve text rects too.
*/
void SetSelection(nsIWidget* aWidget,
uint32_t aStartOffset,
uint32_t aLength,
bool aReversed,
const WritingMode& aWritingMode);
private:
bool QueryCharRect(nsIWidget* aWidget,
uint32_t aOffset,
LayoutDeviceIntRect& aCharRect) const;
bool CacheCaret(nsIWidget* aWidget,
const IMENotification* aNotification = nullptr);
bool CacheTextRects(nsIWidget* aWidget,
const IMENotification* aNotification = nullptr);
};
class ContentCacheInParent final : public ContentCache
{
public:
ContentCacheInParent();
/**
* AssignContent() is called when TabParent receives ContentCache from
* the content process. This doesn't copy composition information because
* it's managed by TabParent itself.
*/
void AssignContent(const ContentCache& aOther,
const IMENotification* aNotification = nullptr);
/**
* HandleQueryContentEvent() sets content data to aEvent.mReply.
*
* For eQuerySelectedText, fail if the cache doesn't contain the whole
* selected range. (This shouldn't happen because PuppetWidget should have
* already sent the whole selection.)
*
* For eQueryTextContent, fail only if the cache doesn't overlap with
* the queried range. Note the difference from above. We use
* this behavior because a normal eQueryTextContent event is allowed to
* have out-of-bounds offsets, so that widget can request content without
* knowing the exact length of text. It's up to widget to handle cases when
* the returned offset/length are different from the queried offset/length.
*
* For eQueryTextRect, fail if cached offset/length aren't equals to input.
* Cocoa widget always queries selected offset, so it works on it.
*
* For eQueryCaretRect, fail if cached offset isn't equals to input
*
* For eQueryEditorRect, always success
*/
bool HandleQueryContentEvent(WidgetQueryContentEvent& aEvent,
nsIWidget* aWidget) const;
/**
* OnCompositionEvent() should be called before sending composition string.
* This returns true if the event should be sent. Otherwise, false.
*/
bool OnCompositionEvent(const WidgetCompositionEvent& aCompositionEvent);
/**
* OnSelectionEvent() should be called before sending selection event.
*/
void OnSelectionEvent(const WidgetSelectionEvent& aSelectionEvent);
/**
* OnEventNeedingAckHandled() should be called after the child process
* handles a sent event which needs acknowledging.
*
* WARNING: This may send notifications to IME. That might cause destroying
* TabParent or aWidget. Therefore, the caller must not destroy
* this instance during a call of this method.
*/
void OnEventNeedingAckHandled(nsIWidget* aWidget, EventMessage aMessage);
/**
* RequestIMEToCommitComposition() requests aWidget to commit or cancel
* composition. If it's handled synchronously, this returns true.
*
* @param aWidget The widget to be requested to commit or cancel
* the composition.
* @param aCancel When the caller tries to cancel the composition, true.
* Otherwise, i.e., tries to commit the composition, false.
* @param aCommittedString The committed string (i.e., the last data of
* dispatched composition events during requesting
* IME to commit composition.
* @return Whether the composition is actually committed
* synchronously.
*/
bool RequestIMEToCommitComposition(nsIWidget* aWidget,
bool aCancel,
nsAString& aCommittedString);
/**
* MaybeNotifyIME() may notify IME of the notification. If child process
* hasn't been handled all sending events yet, this stores the notification
* and flush it later.
*/
void MaybeNotifyIME(nsIWidget* aWidget,
const IMENotification& aNotification);
private:
IMENotification mPendingSelectionChange;
IMENotification mPendingTextChange;
IMENotification mPendingLayoutChange;
IMENotification mPendingCompositionUpdate;
// This is not nullptr only while the instance is requesting IME to
// composition. Then, data value of dispatched composition events should
// be stored into the instance.
nsAString* mCommitStringByRequest;
// Start offset of the composition string.
uint32_t mCompositionStart;
// mPendingEventsNeedingAck is increased before sending a composition event or
// a selection event and decreased after they are received in the child
// process.
uint32_t mPendingEventsNeedingAck;
bool mIsComposing;
bool GetCaretRect(uint32_t aOffset, LayoutDeviceIntRect& aCaretRect) const;
bool GetTextRect(uint32_t aOffset,
LayoutDeviceIntRect& aTextRect) const;
bool GetUnionTextRects(uint32_t aOffset,
uint32_t aLength,
LayoutDeviceIntRect& aUnionTextRect) const;
void FlushPendingNotifications(nsIWidget* aWidget);
};
} // namespace mozilla
#endif // mozilla_ContentCache_h