| /* |
| * Copyright 2019 Google Inc. |
| * |
| * 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 LIB_TXT_SRC_PLACEHOLDER_RUN_H_ |
| #define LIB_TXT_SRC_PLACEHOLDER_RUN_H_ |
| |
| #include "text_baseline.h" |
| |
| namespace txt { |
| |
| /// Where to vertically align the placeholder relative to the surrounding text. |
| enum class PlaceholderAlignment { |
| /// Match the baseline of the placeholder with the baseline. |
| kBaseline, |
| |
| /// Align the bottom edge of the placeholder with the baseline such that the |
| /// placeholder sits on top of the baseline. |
| kAboveBaseline, |
| |
| /// Align the top edge of the placeholder with the baseline specified in |
| /// such that the placeholder hangs below the baseline. |
| kBelowBaseline, |
| |
| /// Align the top edge of the placeholder with the top edge of the font. |
| /// When the placeholder is very tall, the extra space will hang from |
| /// the top and extend through the bottom of the line. |
| kTop, |
| |
| /// Align the bottom edge of the placeholder with the top edge of the font. |
| /// When the placeholder is very tall, the extra space will rise from |
| /// the bottom and extend through the top of the line. |
| kBottom, |
| |
| /// Align the middle of the placeholder with the middle of the text. When the |
| /// placeholder is very tall, the extra space will grow equally from |
| /// the top and bottom of the line. |
| kMiddle, |
| }; |
| |
| // Represents the metrics required to fully define a rect that will fit a |
| // placeholder. |
| // |
| // LibTxt will leave an empty space in the layout of the text of the size |
| // defined by this class. After layout, the framework will draw placeholders |
| // into the reserved space. |
| class PlaceholderRun { |
| public: |
| double width = 0; |
| double height = 0; |
| |
| PlaceholderAlignment alignment; |
| |
| TextBaseline baseline; |
| |
| // Distance from the top edge of the rect to the baseline position. This |
| // baseline will be aligned against the alphabetic baseline of the surrounding |
| // text. |
| // |
| // Positive values drop the baseline lower (positions the rect higher) and |
| // small or negative values will cause the rect to be positioned underneath |
| // the line. When baseline == height, the bottom edge of the rect will rest on |
| // the alphabetic baseline. |
| double baseline_offset = 0; |
| |
| PlaceholderRun(); |
| |
| PlaceholderRun(double width, |
| double height, |
| PlaceholderAlignment alignment, |
| TextBaseline baseline, |
| double baseline_offset); |
| }; |
| |
| } // namespace txt |
| |
| #endif // LIB_TXT_SRC_PLACEHOLDER_RUN_H_ |