| /* |
| * Copyright 2019 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.ui.input |
| |
| import androidx.compose.Immutable |
| import androidx.compose.Stable |
| import androidx.compose.runtime.savedinstancestate.Saver |
| import androidx.compose.runtime.savedinstancestate.listSaver |
| import androidx.ui.text.TextRange |
| import androidx.ui.text.substring |
| import kotlin.math.max |
| import kotlin.math.min |
| |
| /** |
| * Stores an input state for IME |
| * |
| * IME can request editor state with calling getTextBeforeCursor, getSelectedText, etc. |
| * This class stores a snapshot of the input state of the edit buffer and provide utility functions |
| * for answering these information retrieval requests. |
| */ |
| @Immutable |
| @Deprecated( |
| "Please use androidx.ui.input.TextFieldValue instead", |
| ReplaceWith("TextFieldValue", "androidx.ui.input.TextFieldValue") |
| ) |
| data class EditorValue( |
| /** |
| * A text visible to IME |
| */ |
| val text: String = "", |
| |
| /** |
| * A selection range visible to IME. |
| * The selection range must be valid range in the given text. |
| */ |
| val selection: TextRange = TextRange.Zero, |
| |
| /** |
| * A composition range visible to IME. |
| * If null, there is no composition range. |
| * If non-null, the composition range must be valid range in the given text. |
| */ |
| val composition: TextRange? = null |
| ) { |
| /** |
| * Helper function for getting text before selection range. |
| */ |
| fun getTextBeforeSelection(maxChars: Int): String = |
| text.substring(max(0, selection.min - maxChars), selection.min) |
| |
| /** |
| * Helper function for getting text after selection range. |
| */ |
| fun getTextAfterSelection(maxChars: Int): String = |
| text.substring(selection.max, min(selection.max + maxChars, text.length)) |
| |
| /** |
| * Helper function for getting text currently selected. |
| */ |
| fun getSelectedText(): String = text.substring(selection) |
| } |
| |
| /** |
| * A class holding information about the editing state. |
| * |
| * The input service updates text selection, cursor, text and text composition. This class |
| * represents those values and it is possible to observe changes to those values in the text |
| * editing composables. |
| * |
| * Input service composition is an instance of text produced by IME. An example visual for the |
| * composition is that the currently composed word is visually separated from others with |
| * underline, or text background. For description of |
| * composition please check [W3C IME Composition](https://www.w3.org/TR/ime-api/#ime-composition) |
| * |
| * This class stores a snapshot of the input state of the edit buffer and provide utility functions |
| * for answering IME requests such as getTextBeforeCursor, getSelectedText. |
| * |
| * @param text the text will be rendered |
| * @param selection the selection range. If the selection is collapsed, it represents cursor |
| * location. Selection range must be within the bounds of the [text], otherwise an exception will be |
| * thrown. |
| * @param composition A composition range visible to IME. If null, there is no composition range. |
| * Composition range must be within the bounds of the [text], otherwise an exception will be |
| * thrown. For description of composition please check [W3C IME Composition](https://www.w3 |
| * .org/TR/ime-api/#ime-composition). |
| */ |
| @Immutable |
| data class TextFieldValue( |
| @Stable |
| val text: String = "", |
| @Stable |
| val selection: TextRange = TextRange.Zero, |
| @Stable |
| val composition: TextRange? = null |
| ) { |
| init { |
| // TextRange end is exclusive therefore can be at the end of the text |
| require(selection.end <= text.length) { |
| "Selection is out of bounds. [selection: $selection, text.length = ${text.length}]" |
| } |
| |
| // TextRange end is exclusive therefore can be at the end of the text |
| composition?.let { |
| require(composition.end <= text.length) { |
| "Composition is out of bounds. " + |
| "[composition: $selection, text.length = ${text.length}]" |
| } |
| } |
| } |
| |
| companion object { |
| /** |
| * The default [Saver] implementation for [TextFieldValue]. |
| */ |
| val Saver = listSaver<TextFieldValue, Any>( |
| save = { |
| listOf(it.text, it.selection.start, it.selection.end) |
| }, |
| restore = { |
| TextFieldValue(it[0] as String, TextRange(it[1] as Int, it[2] as Int)) |
| } |
| ) |
| } |
| } |
| |
| /** |
| * Helper function for getting text before selection range. |
| */ |
| fun TextFieldValue.getTextBeforeSelection(maxChars: Int): String = |
| text.substring(max(0, selection.min - maxChars), selection.min) |
| |
| /** |
| * Helper function for getting text after selection range. |
| */ |
| fun TextFieldValue.getTextAfterSelection(maxChars: Int): String = |
| text.substring(selection.max, min(selection.max + maxChars, text.length)) |
| |
| /** |
| * Helper function for getting text currently selected. |
| */ |
| fun TextFieldValue.getSelectedText(): String = text.substring(selection) |