| /* |
| * Copyright 2020 The Android Open Source Project |
| * |
| * 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. |
| */ |
| |
| package androidx.compose.foundation.text |
| |
| import androidx.compose.Composable |
| import androidx.compose.ui.text.AnnotatedString |
| import androidx.compose.ui.text.Placeholder |
| |
| /** The annotation tag used by inline content. */ |
| internal const val INLINE_CONTENT_TAG = "androidx.compose.foundation.text.inlineContent" |
| // A string that contains a replacement character specified by unicode. It's used as the default |
| // value of alternate text. |
| private const val REPLACEMENT_CHAR = "\uFFFD" |
| /** |
| * Append an inline content into the AnnotatedString. |
| * @param id The id of this inline content, it is referred by the [androidx.compose.foundation.text.CoreText] |
| * parameter inlineContent to replace the [alternateText] to the corresponding composable. |
| * @param alternateText The text to be replaced by the inline content. It's displayed when |
| * the inlineContent parameter of [androidx.compose.foundation.text.CoreText] doesn't contain [id]. Accessibility |
| * features will also use this text to describe the inline content. |
| * @throws IllegalArgumentException if [alternateText] has zero length. |
| */ |
| fun AnnotatedString.Builder.appendInlineContent( |
| id: String, |
| alternateText: String = REPLACEMENT_CHAR |
| ) { |
| require(alternateText.length > 0) { |
| "alternateText can't be an empty string." |
| } |
| pushStringAnnotation(INLINE_CONTENT_TAG, id) |
| append(alternateText) |
| pop() |
| } |
| |
| /** |
| * A data class that stores a composable to be inserted into the text layout. |
| * |
| * Different from a regular composable, a [Placeholder] is also needed for text layout to reserve |
| * space. In this [placeholder], the size of the content and how it will be aligned within the |
| * text line is defined. When the children composable is measured, its size given in |
| * [Placeholder.width] and [Placeholder.height] will be converted into |
| * [androidx.ui.core.Constraints] and passed through [androidx.ui.core.Layout]. |
| * |
| * @sample androidx.compose.foundation.text.samples.InlineTextContentSample |
| * @see CoreText |
| * @see Placeholder |
| */ |
| data class InlineTextContent( |
| /** |
| * The setting object that defines the size and vertical alignment of this composable in the |
| * text line. This is different from the measure of Layout |
| * @see Placeholder |
| */ |
| val placeholder: Placeholder, |
| /** |
| * The composable to be inserted into the text layout. |
| * The string parameter passed to it will the alternateText given to [appendInlineContent]. |
| */ |
| val children: @Composable() (String) -> Unit |
| ) |