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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;
+
+ // Start offset of the composition string.
+ uint32_t mCompositionStart;
+
+ enum
+ {
+ ePrevCharRect = 1,
+ eNextCharRect = 0
+ };
+
+ struct Selection final
+ {
+ // Following values are offset in "flat text".
+ uint32_t mAnchor;
+ uint32_t mFocus;
+
+ WritingMode mWritingMode;
+
+ // Character rects at previous and next character of mAnchor and mFocus.
+ // The reason why ContentCache needs to store each previous character of
+ // them is IME may query character rect of the last character of a line
+ // when caret is at the end of the line.
+ // Note that use ePrevCharRect and eNextCharRect for accessing each item.
+ LayoutDeviceIntRect mAnchorCharRects[2];
+ LayoutDeviceIntRect mFocusCharRects[2];
+
+ // 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();
+ ClearAnchorCharRects();
+ ClearFocusCharRects();
+ mRect.SetEmpty();
+ }
+
+ void ClearAnchorCharRects()
+ {
+ for (size_t i = 0; i < ArrayLength(mAnchorCharRects); i++) {
+ mAnchorCharRects[i].SetEmpty();
+ }
+ }
+ void ClearFocusCharRects()
+ {
+ for (size_t i = 0; i < ArrayLength(mFocusCharRects); i++) {
+ mFocusCharRects[i].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;
+ }
+ LayoutDeviceIntRect StartCharRect() const
+ {
+ NS_ASSERTION(IsValid(),
+ "The caller should check if the selection is valid");
+ return Reversed() ? mFocusCharRects[eNextCharRect] :
+ mAnchorCharRects[eNextCharRect];
+ }
+ LayoutDeviceIntRect EndCharRect() const
+ {
+ NS_ASSERTION(IsValid(),
+ "The caller should check if the selection is valid");
+ return Reversed() ? mAnchorCharRects[eNextCharRect] :
+ mFocusCharRects[eNextCharRect];
+ }
+ } 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();
+ }
+ bool HasRects() const
+ {
+ return IsValid() && !mRects.IsEmpty();
+ }
+ 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 (!HasRects() || aOffset == UINT32_MAX || !aLength) {
+ 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,
+ bool aRoundToExistingOffset) 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 QueryCharRectArray(nsIWidget* aWidget,
+ uint32_t aOffset,
+ uint32_t aLength,
+ RectArray& aCharRectArray) 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,
+ nsIWidget* aWidget,
+ 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;
+ // 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;
+ // mCompositionStartInChild stores current composition start offset in the
+ // remote process.
+ uint32_t mCompositionStartInChild;
+ // mPendingCompositionCount is number of compositions which started in widget
+ // but not yet handled in the child process.
+ uint8_t mPendingCompositionCount;
+ // mWidgetHasComposition is true when the widget in this process thinks that
+ // IME has composition. So, this is set to true when eCompositionStart is
+ // dispatched and set to false when eCompositionCommit(AsIs) is dispatched.
+ bool mWidgetHasComposition;
+
+ /**
+ * When following methods' aRoundToExistingOffset is true, even if specified
+ * offset or range is out of bounds, the result is computed with the existing
+ * cache forcibly.
+ */
+ bool GetCaretRect(uint32_t aOffset,
+ bool aRoundToExistingOffset,
+ LayoutDeviceIntRect& aCaretRect) const;
+ bool GetTextRect(uint32_t aOffset,
+ bool aRoundToExistingOffset,
+ LayoutDeviceIntRect& aTextRect) const;
+ bool GetUnionTextRects(uint32_t aOffset,
+ uint32_t aLength,
+ bool aRoundToExistingOffset,
+ LayoutDeviceIntRect& aUnionTextRect) const;
+
+ void FlushPendingNotifications(nsIWidget* aWidget);
+};
+
+} // namespace mozilla
+
+#endif // mozilla_ContentCache_h