michael@0: /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
michael@0:  * This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "gfxCachedTempSurface.h"
michael@0: #include "gfxContext.h"
michael@0: #include "mozilla/Attributes.h"
michael@0: 
michael@0: class CachedSurfaceExpirationTracker MOZ_FINAL :
michael@0:   public nsExpirationTracker<gfxCachedTempSurface,2> {
michael@0: 
michael@0: public:
michael@0:   // With K = 2, this means that surfaces will be released when they are not
michael@0:   // used for 1-2 seconds.
michael@0:   enum { TIMEOUT_MS = 1000 };
michael@0:   CachedSurfaceExpirationTracker()
michael@0:     : nsExpirationTracker<gfxCachedTempSurface,2>(TIMEOUT_MS) {}
michael@0: 
michael@0:   ~CachedSurfaceExpirationTracker() {
michael@0:     AgeAllGenerations();
michael@0:   }
michael@0: 
michael@0:   virtual void NotifyExpired(gfxCachedTempSurface* aSurface) {
michael@0:     RemoveObject(aSurface);
michael@0:     aSurface->Expire();
michael@0:   }
michael@0: 
michael@0:   static void MarkSurfaceUsed(gfxCachedTempSurface* aSurface)
michael@0:   {
michael@0:     if (aSurface->GetExpirationState()->IsTracked()) {
michael@0:       sExpirationTracker->MarkUsed(aSurface);
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     if (!sExpirationTracker) {
michael@0:       sExpirationTracker = new CachedSurfaceExpirationTracker();
michael@0:     }
michael@0:     sExpirationTracker->AddObject(aSurface);
michael@0:   }
michael@0: 
michael@0:   static void RemoveSurface(gfxCachedTempSurface* aSurface)
michael@0:   {
michael@0:     if (!sExpirationTracker)
michael@0:       return;
michael@0: 
michael@0:     if (aSurface->GetExpirationState()->IsTracked()) {
michael@0:       sExpirationTracker->RemoveObject(aSurface);
michael@0:     }
michael@0:     if (sExpirationTracker->IsEmpty()) {
michael@0:       delete sExpirationTracker;
michael@0:       sExpirationTracker = nullptr;
michael@0:     }
michael@0:   }
michael@0: 
michael@0: private:
michael@0:   static CachedSurfaceExpirationTracker* sExpirationTracker;
michael@0: };
michael@0: 
michael@0: CachedSurfaceExpirationTracker*
michael@0: CachedSurfaceExpirationTracker::sExpirationTracker = nullptr;
michael@0: 
michael@0: gfxCachedTempSurface::~gfxCachedTempSurface()
michael@0: {
michael@0:   CachedSurfaceExpirationTracker::RemoveSurface(this);
michael@0: }
michael@0: 
michael@0: already_AddRefed<gfxContext>
michael@0: gfxCachedTempSurface::Get(gfxContentType aContentType,
michael@0:                           const gfxRect& aRect,
michael@0:                           gfxASurface* aSimilarTo)
michael@0: {
michael@0:   if (mSurface) {
michael@0:     /* Verify the current buffer is valid for this purpose */
michael@0:     if (mSize.width < aRect.width || mSize.height < aRect.height
michael@0:         || mSurface->GetContentType() != aContentType
michael@0:         || mType != aSimilarTo->GetType()) {
michael@0:       mSurface = nullptr;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   bool cleared = false;
michael@0:   if (!mSurface) {
michael@0:     mSize = gfxIntSize(int32_t(ceil(aRect.width)), int32_t(ceil(aRect.height)));
michael@0:     mSurface = aSimilarTo->CreateSimilarSurface(aContentType, mSize);
michael@0:     if (!mSurface)
michael@0:       return nullptr;
michael@0: 
michael@0:     cleared = true;
michael@0:     mType = aSimilarTo->GetType();
michael@0:   }
michael@0:   mSurface->SetDeviceOffset(-aRect.TopLeft());
michael@0: 
michael@0:   nsRefPtr<gfxContext> ctx = new gfxContext(mSurface);
michael@0:   ctx->Rectangle(aRect);
michael@0:   ctx->Clip();
michael@0:   if (!cleared && aContentType != gfxContentType::COLOR) {
michael@0:     ctx->SetOperator(gfxContext::OPERATOR_CLEAR);
michael@0:     ctx->Paint();
michael@0:     ctx->SetOperator(gfxContext::OPERATOR_OVER);
michael@0:   }
michael@0: 
michael@0:   CachedSurfaceExpirationTracker::MarkSurfaceUsed(this);
michael@0: 
michael@0:   return ctx.forget();
michael@0: }