| // 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 CONTENT_RENDERER_ACCESSIBILITY_BLINK_AX_TREE_SOURCE_H_ |
| #define CONTENT_RENDERER_ACCESSIBILITY_BLINK_AX_TREE_SOURCE_H_ |
| |
| #include <stdint.h> |
| |
| #include <set> |
| #include <string> |
| |
| #include "base/optional.h" |
| #include "content/common/ax_content_node_data.h" |
| #include "third_party/blink/public/web/web_ax_object.h" |
| #include "third_party/blink/public/web/web_document.h" |
| #include "ui/accessibility/ax_mode.h" |
| #include "ui/accessibility/ax_node_data.h" |
| #include "ui/accessibility/ax_tree_data.h" |
| #include "ui/accessibility/ax_tree_source.h" |
| |
| namespace content { |
| |
| class AXImageAnnotator; |
| class BlinkAXTreeSource; |
| class RenderFrameImpl; |
| |
| // Create this on the stack to freeze BlinkAXTreeSource and automatically |
| // un-freeze it when it goes out of scope. |
| class ScopedFreezeBlinkAXTreeSource { |
| public: |
| explicit ScopedFreezeBlinkAXTreeSource(BlinkAXTreeSource* tree_source); |
| ~ScopedFreezeBlinkAXTreeSource(); |
| |
| private: |
| BlinkAXTreeSource* tree_source_; |
| |
| DISALLOW_COPY_AND_ASSIGN(ScopedFreezeBlinkAXTreeSource); |
| }; |
| |
| class CONTENT_EXPORT BlinkAXTreeSource |
| : public ui:: |
| AXTreeSource<blink::WebAXObject, AXContentNodeData, ui::AXTreeData> { |
| public: |
| BlinkAXTreeSource(RenderFrameImpl* render_frame, ui::AXMode mode); |
| ~BlinkAXTreeSource() override; |
| |
| // Freeze caches the document, accessibility root, and current focused |
| // object for fast retrieval during a batch of operations. Use |
| // ScopedFreezeBlinkAXTreeSource on the stack rather than calling |
| // these directly. |
| void Freeze(); |
| void Thaw(); |
| |
| // It may be necessary to call SetRoot if you're using a WebScopedAXContext, |
| // because BlinkAXTreeSource can't get the root of the tree from the |
| // WebDocument if accessibility isn't enabled globally. |
| void SetRoot(blink::WebAXObject root); |
| |
| // Walks up the ancestor chain to see if this is a descendant of the root. |
| bool IsInTree(blink::WebAXObject node) const; |
| |
| ui::AXMode accessibility_mode() { return accessibility_mode_; } |
| void SetAccessibilityMode(ui::AXMode new_mode); |
| |
| // Set the id of the node to fetch image data for. Normally the content |
| // of images is not part of the accessibility tree, but one node at a |
| // time can be designated as the image data node, which will send the |
| // contents of the image with each accessibility update until another |
| // node is designated. |
| int image_data_node_id() { return image_data_node_id_; } |
| void set_image_data_node_id(int id) { image_data_node_id_ = id; } |
| |
| void set_max_image_data_size(const gfx::Size& size) { |
| max_image_data_size_ = size; |
| } |
| |
| // The following methods add or remove an image annotator which is used to |
| // provide automatic labels for images. |
| void AddImageAnnotator(AXImageAnnotator* const annotator) { |
| DCHECK_EQ(image_annotator_, nullptr); |
| DCHECK(!first_unlabeled_image_id_.has_value()); |
| image_annotator_ = annotator; |
| } |
| void RemoveImageAnnotator() { |
| image_annotator_ = nullptr; |
| first_unlabeled_image_id_ = base::nullopt; |
| } |
| |
| // Query or update a set of IDs for which we should load inline text boxes. |
| bool ShouldLoadInlineTextBoxes(const blink::WebAXObject& obj) const; |
| void SetLoadInlineTextBoxesForId(int32_t id); |
| |
| // AXTreeSource implementation. |
| bool GetTreeData(ui::AXTreeData* tree_data) const override; |
| blink::WebAXObject GetRoot() const override; |
| blink::WebAXObject GetFromId(int32_t id) const override; |
| int32_t GetId(blink::WebAXObject node) const override; |
| void GetChildren( |
| blink::WebAXObject node, |
| std::vector<blink::WebAXObject>* out_children) const override; |
| blink::WebAXObject GetParent(blink::WebAXObject node) const override; |
| void SerializeNode(blink::WebAXObject node, |
| AXContentNodeData* out_data) const override; |
| bool IsIgnored(blink::WebAXObject node) const override; |
| bool IsValid(blink::WebAXObject node) const override; |
| bool IsEqual(blink::WebAXObject node1, |
| blink::WebAXObject node2) const override; |
| blink::WebAXObject GetNull() const override; |
| std::string GetDebugString(blink::WebAXObject node) const override; |
| |
| blink::WebDocument GetMainDocument() const; |
| |
| private: |
| const blink::WebDocument& document() const { |
| DCHECK(frozen_); |
| return document_; |
| } |
| const blink::WebAXObject& root() const { |
| DCHECK(frozen_); |
| return root_; |
| } |
| const blink::WebAXObject& focus() const { |
| DCHECK(frozen_); |
| return focus_; |
| } |
| |
| void SerializeBoundingBoxAttributes(blink::WebAXObject src, |
| AXContentNodeData* dst) const; |
| void SerializePDFAttributes(blink::WebAXObject src, |
| AXContentNodeData* dst) const; |
| void SerializeSparseAttributes(blink::WebAXObject src, |
| AXContentNodeData* dst) const; |
| void SerializeNameAndDescriptionAttributes(blink::WebAXObject src, |
| AXContentNodeData* dst) const; |
| void SerializeValueAttributes(blink::WebAXObject src, |
| AXContentNodeData* dst) const; |
| void SerializeStateAttributes(blink::WebAXObject src, |
| AXContentNodeData* dst) const; |
| void SerializeStyleAttributes(blink::WebAXObject src, |
| AXContentNodeData* dst) const; |
| void SerializeInlineTextBoxAttributes(blink::WebAXObject src, |
| AXContentNodeData* dst) const; |
| void SerializeMarkerAttributes(blink::WebAXObject src, |
| AXContentNodeData* dst) const; |
| void SerializeLiveRegionAttributes(blink::WebAXObject src, |
| AXContentNodeData* dst) const; |
| void SerializeListAttributes(blink::WebAXObject src, |
| AXContentNodeData* dst) const; |
| void SerializeTableAttributes(blink::WebAXObject src, |
| AXContentNodeData* dst) const; |
| void SerializeScrollAttributes(blink::WebAXObject src, |
| AXContentNodeData* dst) const; |
| void SerializeChooserPopupAttributes(blink::WebAXObject src, |
| AXContentNodeData* dst) const; |
| void SerializeOtherScreenReaderAttributes(blink::WebAXObject src, |
| AXContentNodeData* dst) const; |
| void SerializeEditableTextAttributes(blink::WebAXObject src, |
| AXContentNodeData* dst) const; |
| void SerializeElementAttributes(blink::WebAXObject src, |
| blink::WebElement element, |
| AXContentNodeData* dst) const; |
| void SerializeHTMLAttributes(blink::WebAXObject src, |
| blink::WebElement element, |
| AXContentNodeData* dst) const; |
| |
| blink::WebAXObject ComputeRoot() const; |
| |
| // Max length for attributes such as aria-label. |
| static const uint32_t kMaxStringAttributeLength = 10000; |
| // Max length for a static text name. |
| // Length of War and Peace (http://www.gutenberg.org/files/2600/2600-0.txt). |
| static const uint32_t kMaxStaticTextLength = 3227574; |
| void TruncateAndAddStringAttribute( |
| AXContentNodeData* dst, |
| ax::mojom::StringAttribute attribute, |
| const std::string& value, |
| uint32_t max_len = kMaxStringAttributeLength) const; |
| |
| void AddImageAnnotations(blink::WebAXObject& src, |
| AXContentNodeData* dst) const; |
| |
| RenderFrameImpl* render_frame_; |
| |
| ui::AXMode accessibility_mode_; |
| |
| // An explicit root to use, otherwise it's taken from the WebDocument. |
| blink::WebAXObject explicit_root_; |
| |
| // A set of IDs for which we should always load inline text boxes. |
| std::set<int32_t> load_inline_text_boxes_ids_; |
| |
| // The ID of the object to fetch image data for. |
| int image_data_node_id_ = -1; |
| |
| gfx::Size max_image_data_size_; |
| |
| // The class instance that retrieves and manages automatic labels for images. |
| AXImageAnnotator* image_annotator_ = nullptr; |
| |
| // Whether we should highlight annotation results visually on the page |
| // for debugging. |
| bool image_annotation_debugging_ = false; |
| |
| // The AxID of the first unlabeled image we have encountered in this tree. |
| // |
| // Used to ensure that the tutor message that explains to screen reader users |
| // how to turn on automatic image labels is provided only once. |
| mutable base::Optional<int32_t> first_unlabeled_image_id_ = base::nullopt; |
| |
| // These are updated when calling |Freeze|. |
| bool frozen_ = false; |
| blink::WebDocument document_; |
| blink::WebAXObject root_; |
| blink::WebAXObject focus_; |
| }; |
| |
| } // namespace content |
| |
| #endif // CONTENT_RENDERER_ACCESSIBILITY_BLINK_AX_TREE_SOURCE_H_ |