| /* |
| * Copyright 2014 Google Inc. All Rights Reserved. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifndef COBALT_LAYOUT_TEXT_BOX_H_ |
| #define COBALT_LAYOUT_TEXT_BOX_H_ |
| |
| #include <string> |
| |
| #include "base/basictypes.h" |
| #include "base/memory/ref_counted.h" |
| #include "cobalt/dom/font_list.h" |
| #include "cobalt/layout/box.h" |
| #include "cobalt/layout/layout_unit.h" |
| #include "cobalt/layout/paragraph.h" |
| #include "cobalt/render_tree/font.h" |
| |
| namespace cobalt { |
| namespace layout { |
| |
| // Although the CSS 2.1 specification assumes that the text is simply a part of |
| // an inline box, it is impractical to implement it that way. Instead, we define |
| // a text box as an anonymous replaced inline-level box that is breakable at |
| // soft wrap opportunities. |
| class TextBox : public Box { |
| public: |
| TextBox(const scoped_refptr<cssom::CSSComputedStyleDeclaration>& |
| css_computed_style_declaration, |
| const scoped_refptr<Paragraph>& paragraph, int32 text_start_position, |
| int32 text_end_position, bool triggers_line_break, |
| bool is_created_from_split, UsedStyleProvider* used_style_provider, |
| LayoutStatTracker* layout_stat_tracker); |
| |
| // From |Box|. |
| Level GetLevel() const OVERRIDE; |
| |
| void UpdateContentSizeAndMargins(const LayoutParams& layout_params) OVERRIDE; |
| |
| WrapResult TryWrapAt(WrapAtPolicy wrap_at_policy, |
| WrapOpportunityPolicy wrap_opportunity_policy, |
| bool is_line_existence_justified, |
| LayoutUnit available_width, |
| bool should_collapse_trailing_white_space) OVERRIDE; |
| |
| Box* GetSplitSibling() const OVERRIDE; |
| |
| bool DoesFulfillEllipsisPlacementRequirement() const OVERRIDE; |
| void DoPreEllipsisPlacementProcessing() OVERRIDE; |
| void DoPostEllipsisPlacementProcessing() OVERRIDE; |
| |
| void SplitBidiLevelRuns() OVERRIDE; |
| bool TrySplitAtSecondBidiLevelRun() OVERRIDE; |
| base::optional<int> GetBidiLevel() const OVERRIDE; |
| |
| void SetShouldCollapseLeadingWhiteSpace( |
| bool should_collapse_leading_white_space) OVERRIDE; |
| void SetShouldCollapseTrailingWhiteSpace( |
| bool should_collapse_trailing_white_space) OVERRIDE; |
| bool HasLeadingWhiteSpace() const OVERRIDE; |
| bool HasTrailingWhiteSpace() const OVERRIDE; |
| bool IsCollapsed() const OVERRIDE; |
| |
| bool JustifiesLineExistence() const OVERRIDE; |
| bool HasTrailingLineBreak() const OVERRIDE; |
| bool AffectsBaselineInBlockFormattingContext() const OVERRIDE; |
| LayoutUnit GetBaselineOffsetFromTopMarginEdge() const OVERRIDE; |
| LayoutUnit GetInlineLevelBoxHeight() const OVERRIDE; |
| LayoutUnit GetInlineLevelTopMargin() const OVERRIDE; |
| |
| bool ValidateUpdateSizeInputs(const LayoutParams& params) OVERRIDE; |
| |
| protected: |
| // From |Box|. |
| void RenderAndAnimateContent(render_tree::CompositionNode::Builder* |
| border_node_builder) const OVERRIDE; |
| bool IsTransformable() const OVERRIDE; |
| |
| #ifdef COBALT_BOX_DUMP_ENABLED |
| void DumpClassName(std::ostream* stream) const OVERRIDE; |
| void DumpProperties(std::ostream* stream) const OVERRIDE; |
| void DumpChildrenWithIndent(std::ostream* stream, int indent) const OVERRIDE; |
| #endif // COBALT_BOX_DUMP_ENABLED |
| |
| private: |
| // From |Box|. |
| void DoPlaceEllipsisOrProcessPlacedEllipsis( |
| BaseDirection base_direction, LayoutUnit desired_offset, |
| bool* is_placement_requirement_met, bool* is_placed, |
| LayoutUnit* placed_offset) OVERRIDE; |
| |
| void UpdateTextHasLeadingWhiteSpace(); |
| void UpdateTextHasTrailingWhiteSpace(); |
| |
| int32 GetWrapPosition(WrapAtPolicy wrap_at_policy, |
| WrapOpportunityPolicy wrap_opportunity_policy, |
| bool is_line_existence_justified, |
| LayoutUnit available_width, |
| bool should_collapse_trailing_white_space, |
| bool style_allows_break_word, int32 start_position); |
| |
| // Split the text box into two. |
| // |split_start_position| indicates the position within the paragraph where |
| // the split occurs and the second box begins |
| void SplitAtPosition(int32 split_start_position); |
| |
| // Width of a space character in the used font, if the box has leading white |
| // space. |
| LayoutUnit GetLeadingWhiteSpaceWidth() const; |
| // Width of a space character in the used font, if the box has trailing white |
| // space. |
| LayoutUnit GetTrailingWhiteSpaceWidth() const; |
| |
| int32 GetNonCollapsedTextStartPosition() const; |
| int32 GetNonCollapsedTextEndPosition() const; |
| |
| int32 GetNonCollapsibleTextStartPosition() const; |
| int32 GetNonCollapsibleTextEndPosition() const; |
| int32 GetNonCollapsibleTextLength() const; |
| bool HasNonCollapsibleText() const; |
| std::string GetNonCollapsibleText() const; |
| |
| int32 GetVisibleTextEndPosition() const; |
| int32 GetVisibleTextLength() const; |
| bool HasVisibleText() const; |
| std::string GetVisibleText() const; |
| |
| // The paragraph that this text box is part of. It contains access to the |
| // underlying text, and handles the logic for determining bidi levels and |
| // where to split the text box during line breaking when the text box does |
| // not fully fit on a line. |
| const scoped_refptr<Paragraph> paragraph_; |
| // The position within the paragraph where the text contained in this box |
| // begins. |
| const int32 text_start_position_; |
| // The position within the paragraph where the text contained in this box |
| // ends. |
| int32 text_end_position_; |
| // The position within the paragraph where the text within the text box is |
| // truncated by an ellipsis and will not be visible. |
| // "Implementations must hide characters and atomic inline-level elements at |
| // the applicable edge(s) of the line as necessary to fit the ellipsis." |
| // https://www.w3.org/TR/css3-ui/#propdef-text-overflow |
| int32 truncated_text_end_position_; |
| // Tracking of the previous value of |truncated_text_end_position_|, which |
| // allows for determination of whether or not the value changed during |
| // ellipsis placement. When this occurs, the cached render tree nodes of this |
| // box and its ancestors are invalidated. |
| int32 previous_truncated_text_end_position_; |
| // The horizontal offset to apply to rendered text as a result of an ellipsis |
| // truncating the text. This value can be non-zero when the text box is in a |
| // line with a right-to-left base direction. In this case, when an ellipsis is |
| // placed, the truncated text is offset to begin to the right of the ellipsis. |
| float truncated_text_offset_from_left_; |
| |
| // A font used for text width and line height calculations. |
| const scoped_refptr<dom::FontList> used_font_; |
| |
| // Whitespace tracking. |
| bool text_has_leading_white_space_; |
| bool text_has_trailing_white_space_; |
| bool should_collapse_leading_white_space_; |
| bool should_collapse_trailing_white_space_; |
| |
| // Specifies whether this text box ends the line it is on, forcing any |
| // additional sibling boxes to be added to a new line. |
| bool has_trailing_line_break_; |
| |
| // A vertical offset of the baseline relatively to the origin of the text box. |
| base::optional<LayoutUnit> baseline_offset_from_top_; |
| |
| // Specifies whether or not this text box was created as a result of the split |
| // of a text box. |
| const bool is_product_of_split_; |
| |
| // A reference to the next text box in a linked list of text boxes produced |
| // from splits of the initial text box. This enables HTMLElement to retain |
| // access to all of its layout boxes after they are split. |
| scoped_refptr<TextBox> split_sibling_; |
| |
| bool update_size_results_valid_; |
| LayoutUnit line_height_; |
| LayoutUnit inline_top_margin_; |
| float ascent_; |
| |
| // The width of the portion of the text that is unaffected by whitespace |
| // collapsing. |
| base::optional<LayoutUnit> non_collapsible_text_width_; |
| }; |
| |
| } // namespace layout |
| } // namespace cobalt |
| |
| #endif // COBALT_LAYOUT_TEXT_BOX_H_ |