Rename DisplayItemList to PaintController

third_party/WebKit/Source/platform/graphics/paint/DisplayItemList.h

-// Copyright 2014 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef DisplayItemList_h
-#define DisplayItemList_h
-
-#include "platform/PlatformExport.h"
-#include "platform/RuntimeEnabledFeatures.h"
-#include "platform/geometry/IntRect.h"
-#include "platform/geometry/LayoutPoint.h"
-#include "platform/graphics/ContiguousContainer.h"
-#include "platform/graphics/PaintInvalidationReason.h"
-#include "platform/graphics/paint/DisplayItem.h"
-#include "platform/graphics/paint/DisplayItems.h"
-#include "platform/graphics/paint/PaintArtifact.h"
-#include "platform/graphics/paint/PaintChunk.h"
-#include "platform/graphics/paint/PaintChunker.h"
-#include "platform/graphics/paint/Transform3DDisplayItem.h"
-#include "wtf/Alignment.h"
-#include "wtf/HashMap.h"
-#include "wtf/PassOwnPtr.h"
-#include "wtf/Utility.h"
-#include "wtf/Vector.h"
-
-namespace blink {
-
-class GraphicsLayer;
-class GraphicsContext;
-
-static const size_t kInitialDisplayItemsCapacity = 64;
-
-// Responsible for processing display items as they are produced, and producing
-// a final paint artifact when complete. This class includes logic for caching,
-// cache invalidation, and merging.
-class PLATFORM_EXPORT DisplayItemList {
-    WTF_MAKE_NONCOPYABLE(DisplayItemList);
-    WTF_MAKE_FAST_ALLOCATED(DisplayItemList);
-public:
-    static PassOwnPtr<DisplayItemList> create()
-    {
-        return adoptPtr(new DisplayItemList());
-    }
-
-    // These methods are called during paint invalidation (or paint if SlimmingPaintSynchronizedPainting is on).
-    void invalidate(const DisplayItemClientWrapper&, PaintInvalidationReason, const IntRect& previousPaintInvalidationRect, const IntRect& newPaintInvalidationRect);
-    void invalidateUntracked(DisplayItemClient);
-    void invalidateAll();
-
-    // Record when paint offsets change during paint.
-    void invalidatePaintOffset(const DisplayItemClientWrapper&);
-#if ENABLE(ASSERT)
-    bool paintOffsetWasInvalidated(DisplayItemClient) const;
-#endif
-
-    // These methods are called during painting.
-
-    // Provide a new set of paint chunk properties to apply to recorded display
-    // items, for Slimming Paint v2.
-    // TODO(pdr): This should be moved to PaintArtifact.
-    void updateCurrentPaintChunkProperties(const PaintChunkProperties&);
-
-    template <typename DisplayItemClass, typename... Args>
-    void createAndAppend(Args&&... args)
-    {
-        static_assert(WTF::IsSubclass<DisplayItemClass, DisplayItem>::value,
-            "Can only createAndAppend subclasses of DisplayItem.");
-        static_assert(sizeof(DisplayItemClass) <= kMaximumDisplayItemSize,
-            "DisplayItem subclass is larger than kMaximumDisplayItemSize.");
-
-        if (displayItemConstructionIsDisabled())
-            return;
-        DisplayItemClass& displayItem = m_newDisplayItems.allocateAndConstruct<DisplayItemClass>(WTF::forward<Args>(args)...);
-        processNewItem(displayItem);
-    }
-
-    // Creates and appends an ending display item to pair with a preceding
-    // beginning item iff the display item actually draws content. For no-op
-    // items, rather than creating an ending item, the begin item will
-    // instead be removed, thereby maintaining brevity of the list. If display
-    // item construction is disabled, no list mutations will be performed.
-    template <typename DisplayItemClass, typename... Args>
-    void endItem(Args&&... args)
-    {
-        if (displayItemConstructionIsDisabled())
-            return;
-        if (lastDisplayItemIsNoopBegin())
-            removeLastDisplayItem();
-        else
-            createAndAppend<DisplayItemClass>(WTF::forward<Args>(args)...);
-    }
-
-    // Scopes must be used to avoid duplicated display item ids when we paint some object
-    // multiple times and generate multiple display items with the same type.
-    // We don't cache display items added in scopes.
-    void beginScope();
-    void endScope();
-
-    // True if the last display item is a begin that doesn't draw content.
-    bool lastDisplayItemIsNoopBegin() const;
-    void removeLastDisplayItem();
-
-    void beginSkippingCache() { ++m_skippingCacheCount; }
-    void endSkippingCache() { ASSERT(m_skippingCacheCount > 0); --m_skippingCacheCount; }
-    bool skippingCache() const { return m_skippingCacheCount; }
-
-    // Must be called when a painting is finished. If passed, invalidations are recorded on the given
-    // GraphicsLayer.
-    void commitNewDisplayItems(GraphicsLayer* = 0);
-
-    // Returns the approximate memory usage, excluding memory likely to be
-    // shared with the embedder after copying to WebDisplayItemList.
-    // Should only be called right after commitNewDisplayItems.
-    size_t approximateUnsharedMemoryUsage() const;
-
-    // Get the artifact generated after the last commit.
-    const PaintArtifact& paintArtifact() const;
-    const DisplayItems& displayItems() const { return paintArtifact().displayItems(); }
-    const Vector<PaintChunk>& paintChunks() const { return paintArtifact().paintChunks(); }
-
-    bool clientCacheIsValid(DisplayItemClient) const;
-
-    bool displayItemConstructionIsDisabled() const { return m_constructionDisabled; }
-    void setDisplayItemConstructionIsDisabled(const bool disable) { m_constructionDisabled = disable; }
-
-    bool textPainted() const { return m_textPainted; }
-    void setTextPainted() { m_textPainted = true; }
-
-    // Returns displayItems added using createAndAppend() since beginning or the last
-    // commitNewDisplayItems(). Use with care.
-    DisplayItems& newDisplayItems() { return m_newDisplayItems; }
-
-#ifndef NDEBUG
-    void showDebugData() const;
-#endif
-
-    void startTrackingPaintInvalidationObjects()
-    {
-        ASSERT(RuntimeEnabledFeatures::slimmingPaintV2Enabled());
-        m_trackedPaintInvalidationObjects = adoptPtr(new Vector<String>());
-    }
-    void stopTrackingPaintInvalidationObjects()
-    {
-        ASSERT(RuntimeEnabledFeatures::slimmingPaintV2Enabled());
-        m_trackedPaintInvalidationObjects = nullptr;
-    }
-    Vector<String> trackedPaintInvalidationObjects()
-    {
-        ASSERT(RuntimeEnabledFeatures::slimmingPaintV2Enabled());
-        return m_trackedPaintInvalidationObjects ? *m_trackedPaintInvalidationObjects : Vector<String>();
-    }
-
-    bool clientHasCheckedPaintInvalidation(DisplayItemClient client) const
-    {
-        ASSERT(RuntimeEnabledFeatures::slimmingPaintSynchronizedPaintingEnabled());
-        return m_clientsCheckedPaintInvalidation.contains(client);
-    }
-    void setClientHasCheckedPaintInvalidation(DisplayItemClient client)
-    {
-        ASSERT(RuntimeEnabledFeatures::slimmingPaintSynchronizedPaintingEnabled());
-        m_clientsCheckedPaintInvalidation.add(client);
-    }
-
-protected:
-    DisplayItemList()
-        : m_newDisplayItems(kInitialDisplayItemsCapacity * kMaximumDisplayItemSize)
-        , m_validlyCachedClientsDirty(false)
-        , m_constructionDisabled(false)
-        , m_textPainted(false)
-        , m_skippingCacheCount(0)
-        , m_numCachedItems(0)
-        , m_nextScope(1) { }
-
-private:
-    // Set new item state (scopes, cache skipping, etc) for a new item.
-    void processNewItem(DisplayItem&);
-
-    void updateValidlyCachedClientsIfNeeded() const;
-
-    void invalidateClient(const DisplayItemClientWrapper&);
-
-#ifndef NDEBUG
-    WTF::String displayItemsAsDebugString(const DisplayItems&) const;
-#endif
-
-    // Indices into PaintList of all DrawingDisplayItems and BeginSubsequenceDisplayItems of each client.
-    // Temporarily used during merge to find out-of-order display items.
-    using DisplayItemIndicesByClientMap = HashMap<DisplayItemClient, Vector<size_t>>;
-
-    static size_t findMatchingItemFromIndex(const DisplayItem::Id&, const DisplayItemIndicesByClientMap&, const DisplayItems&);
-    static void addItemToIndexIfNeeded(const DisplayItem&, size_t index, DisplayItemIndicesByClientMap&);
-
-    struct OutOfOrderIndexContext;
-    DisplayItems::iterator findOutOfOrderCachedItem(const DisplayItem::Id&, OutOfOrderIndexContext&);
-    DisplayItems::iterator findOutOfOrderCachedItemForward(const DisplayItem::Id&, OutOfOrderIndexContext&);
-    void copyCachedSubsequence(DisplayItems::iterator& currentIt, DisplayItems& updatedList);
-
-#if ENABLE(ASSERT)
-    // The following two methods are for checking under-invalidations
-    // (when RuntimeEnabledFeatures::slimmingPaintUnderInvalidationCheckingEnabled).
-    void checkUnderInvalidation(DisplayItems::iterator& newIt, DisplayItems::iterator& currentIt);
-    void checkCachedDisplayItemIsUnchanged(const char* messagePrefix, const DisplayItem& newItem, const DisplayItem& oldItem);
-    void checkNoRemainingCachedDisplayItems();
-#endif
-
-    // The last complete paint artifact.
-    // In SPv2, this includes paint chunks as well as display items.
-    PaintArtifact m_currentPaintArtifact;
-
-    // Data being used to build the next paint artifact.
-    DisplayItems m_newDisplayItems;
-    PaintChunker m_newPaintChunks;
-
-    // Contains all clients having valid cached paintings if updated.
-    // It's lazily updated in updateValidlyCachedClientsIfNeeded().
-    // TODO(wangxianzhu): In the future we can replace this with client-side repaint flags
-    // to avoid the cost of building and querying the hash table.
-    mutable HashSet<DisplayItemClient> m_validlyCachedClients;
-    mutable bool m_validlyCachedClientsDirty;
-
-    // Used during painting. Contains clients that have checked paint invalidation and
-    // are known to be valid.
-    // TODO(wangxianzhu): Use client side flag to avoid const of hash table.
-    HashSet<DisplayItemClient> m_clientsCheckedPaintInvalidation;
-
-#if ENABLE(ASSERT)
-    // Set of clients which had paint offset changes since the last commit. This is used for
-    // ensuring paint offsets are only updated once and are the same in all phases.
-    HashSet<DisplayItemClient> m_clientsWithPaintOffsetInvalidations;
-#endif
-
-    // Allow display item construction to be disabled to isolate the costs of construction
-    // in performance metrics.
-    bool m_constructionDisabled;
-
-    // Indicates this DisplayItemList has ever had text. It is never reset to false.
-    bool m_textPainted;
-
-    int m_skippingCacheCount;
-
-    int m_numCachedItems;
-
-    unsigned m_nextScope;
-    Vector<unsigned> m_scopeStack;
-
-    struct Invalidation {
-        IntRect rect;
-        PaintInvalidationReason invalidationReason;
-    };
-
-    Vector<Invalidation> m_invalidations;
-
-#if ENABLE(ASSERT)
-    // This is used to check duplicated ids during add(). We could also check during
-    // updatePaintList(), but checking during add() helps developer easily find where
-    // the duplicated ids are from.
-    DisplayItemIndicesByClientMap m_newDisplayItemIndicesByClient;
-#endif
-
-    OwnPtr<Vector<String>> m_trackedPaintInvalidationObjects;
-};
-
-} // namespace blink
-
-#endif // DisplayItemList_h