1 files changed, 137 insertions, 0 deletions
diff --git a/webkit/glue/stacking_order_iterator.cc b/webkit/glue/stacking_order_iterator.cc
new file mode 100755
index 0000000..b726a8a
--- /dev/null
+++ b/webkit/glue/stacking_order_iterator.cc
@@ -0,0 +1,137 @@
+// Copyright (c) 2006-2008 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.
+
+#include "config.h"
+
+#pragma warning(push, 0)
+#include "RenderLayer.h"
+#include "RenderObject.h"
+#pragma warning(pop)
+#undef LOG
+
+#include "webkit/glue/stacking_order_iterator.h"
+
+//
+// RenderLayerIterator
+//
+
+RenderLayerIterator::RenderLayerIterator() {
+}
+
+void RenderLayerIterator::Reset(WebCore::RenderLayer* rl) {
+  if (rl) {
+    context_stack_.push_back(Context(rl));
+  }
+}
+
+WebCore::RenderLayer* RenderLayerIterator::Next() {
+  while (context_stack_.size()) {
+    Context* ctx = &(context_stack_.back());
+    if (ctx->HasMoreNeg()) {
+      context_stack_.push_back(ctx->NextNeg());
+    } else if (ctx->HasSelf()) {
+      // Emit self.
+      return ctx->NextSelf();
+    } else if (ctx->HasMoreOverflow()) {
+      context_stack_.push_back(ctx->NextOverflow());
+    } else if (ctx->HasMorePos()) {
+      context_stack_.push_back(ctx->NextPos());
+    } else {
+      // Nothing left in this context.  Pop.
+      context_stack_.pop_back();
+    }
+  }
+  return NULL;
+}
+
+RenderLayerIterator::Context::Context(WebCore::RenderLayer* layer)
+   :  layer_(layer),
+      next_neg_(0),
+      next_self_(0),
+      next_overflow_(0),
+      next_pos_(0) {
+  ASSERT(layer_);
+  layer_->updateZOrderLists();
+  layer_->updateOverflowList();
+}
+
+bool RenderLayerIterator::Context::HasMoreNeg() {
+  return layer_->negZOrderList() &&
+    next_neg_ < layer_->negZOrderList()->size();
+}
+
+RenderLayerIterator::Context RenderLayerIterator::Context::NextNeg() {
+  ASSERT(HasMoreNeg());
+  return Context(layer_->negZOrderList()->at(next_neg_++));
+}
+
+bool RenderLayerIterator::Context::HasSelf() {
+  return next_self_ < 1;
+}
+
+WebCore::RenderLayer* RenderLayerIterator::Context::NextSelf() {
+  ASSERT(HasSelf());
+  next_self_ = 1;
+  return layer_;
+}
+
+bool RenderLayerIterator::Context::HasMoreOverflow() {
+  return layer_->overflowList() &&
+    next_overflow_ >= 0 &&
+    next_overflow_ < layer_->overflowList()->size();
+}
+
+RenderLayerIterator::Context RenderLayerIterator::Context::NextOverflow() {
+  ASSERT(HasMoreOverflow());
+  return Context(layer_->overflowList()->at(next_overflow_++));
+}
+
+bool RenderLayerIterator::Context::HasMorePos() {
+  return layer_->posZOrderList() &&
+    next_pos_ < layer_->posZOrderList()->size();
+}
+
+RenderLayerIterator::Context RenderLayerIterator::Context::NextPos() {
+  ASSERT(HasMorePos());
+  return Context(layer_->posZOrderList()->at(next_pos_++));
+}
+
+//
+// StackingOrderIterator
+//
+
+StackingOrderIterator::StackingOrderIterator() {
+  Reset(NULL);
+}
+
+void StackingOrderIterator::Reset(WebCore::RenderLayer* rl) {
+  layer_iterator_.Reset(rl);
+  current_object_ = NULL;
+  current_layer_root_ = NULL;
+}
+
+WebCore::RenderObject* StackingOrderIterator::Next() {
+  if (current_object_) {
+    // Get the next object inside the current layer.
+    current_object_ = current_object_->nextInPreOrder(current_layer_root_);
+
+    // Skip any sub-layers we encounter along the way; they are
+    // visited (in the correct stacking order) by layer_iterator_.
+    while (current_object_ && current_object_->hasLayer()) {
+      current_object_ = current_object_->
+                        nextInPreOrderAfterChildren(current_layer_root_);
+    }
+  }
+
+  if (!current_object_) {
+    // Start the next layer.
+    WebCore::RenderLayer* layer = layer_iterator_.Next();
+    if (layer) {
+      current_object_ = layer->renderer();
+      current_layer_root_ = current_object_;
+    }
+    // No more layers.
+  }
+  return current_object_;
+}