Builder class for SkLayerDrawLooper.

src/effects/SkLayerDrawLooper.cpp

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SkCanvas.h"
 #include "SkColor.h"
 #include "SkReadBuffer.h"
@@ skipping 211 matching lines @@
 }
 
 SkLayerDrawLooper::SkLayerDrawLooper(SkReadBuffer& buffer)
         : INHERITED(buffer),
           fRecs(NULL),
           fTopRec(NULL),
           fCount(0),
           fCurrRec(NULL) {
     int count = buffer.readInt();
 
+    Builder builder;
     for (int i = 0; i < count; i++) {
         LayerInfo info;
         info.fFlagsMask = buffer.readInt();
         info.fPaintBits = buffer.readInt();
         info.fColorMode = (SkXfermode::Mode)buffer.readInt();
         buffer.readPoint(&info.fOffset);
         info.fPostTranslate = buffer.readBool();
-        buffer.readPaint(this->addLayerOnTop(info));
+        buffer.readPaint(builder.addLayerOnTop(info));
     }
+    builder.initLooperAndReset(this);

[scroggo, 2014/02/11 14:48:37]

I think the main place this will be called is readFlattenable(). What if we made
the caller call the builder instead of using this constructor? Other
flattenables we create builders for can work the same way.

     SkASSERT(count == fCount);
 
 #ifdef SK_DEBUG
     {
         Rec* rec = fRecs;
         int n = 0;
         while (rec) {
             rec = rec->fNext;
             n += 1;
         }
@@ skipping 89 matching lines @@
             str->append("true ");
         } else {
             str->append("false ");
         }
 
         rec->fPaint.toString(str);
         rec = rec->fNext;
     }
 }
 #endif
+
+SkLayerDrawLooper::Builder::Builder()
+        : fRecs(NULL),
+          fTopRec(NULL),
+          fCount(0) {
+}
+
+SkLayerDrawLooper::Builder::~Builder() {
+    Rec* rec = fRecs;
+    while (rec) {
+        Rec* next = rec->fNext;
+        SkDELETE(rec);
+        rec = next;
+    }
+}
+
+SkPaint* SkLayerDrawLooper::Builder::addLayer(const LayerInfo& info) {
+    fCount += 1;
+
+    Rec* rec = SkNEW(Rec);
+    rec->fNext = fRecs;
+    rec->fInfo = info;
+    fRecs = rec;
+    if (NULL == fTopRec) {
+        fTopRec = rec;
+    }
+
+    return &rec->fPaint;
+}
+
+void SkLayerDrawLooper::Builder::addLayer(SkScalar dx, SkScalar dy) {
+    LayerInfo info;
+
+    info.fOffset.set(dx, dy);
+    (void)this->addLayer(info);
+}
+
+SkPaint* SkLayerDrawLooper::Builder::addLayerOnTop(const LayerInfo& info) {
+    fCount += 1;
+
+    Rec* rec = SkNEW(Rec);
+    rec->fNext = NULL;
+    rec->fInfo = info;
+    if (NULL == fRecs) {
+        fRecs = rec;
+    } else {
+        SkASSERT(NULL != fTopRec);
+        fTopRec->fNext = rec;
+    }
+    fTopRec = rec;
+
+    return &rec->fPaint;
+}
+
+SkLayerDrawLooper* SkLayerDrawLooper::Builder::detachLooper() {
+    SkLayerDrawLooper* looper = SkNEW(SkLayerDrawLooper);
+    initLooperAndReset(looper);
+    return looper;
+}
+
+void SkLayerDrawLooper::Builder::initLooperAndReset(SkLayerDrawLooper* looper) {
+    looper->fCount = fCount;
+    looper->fRecs = fRecs;
+
+    fCount = 0;
+    fRecs = NULL;
+    fTopRec = NULL;
+}