| /* |
| * 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 |
| |
| import androidx.compose.foundation.layout.ColumnScope |
| import androidx.compose.foundation.layout.Spacer |
| import androidx.compose.runtime.Composable |
| import androidx.compose.ui.Modifier |
| import androidx.compose.ui.draw.drawBehind |
| import androidx.compose.ui.graphics.drawscope.DrawScope |
| import androidx.compose.ui.semantics.contentDescription |
| import androidx.compose.ui.semantics.semantics |
| |
| /** |
| * Component that allow you to specify an area on the screen and perform canvas drawing on this |
| * area. You MUST specify size with modifier, whether with exact sizes via [Modifier.size] |
| * modifier, or relative to parent, via [Modifier.fillMaxSize], [ColumnScope.weight], etc. If parent |
| * wraps this child, only exact sizes must be specified. |
| * |
| * @sample androidx.compose.foundation.samples.CanvasSample |
| * |
| * @param modifier mandatory modifier to specify size strategy for this composable |
| * @param onDraw lambda that will be called to perform drawing. Note that this lambda will be |
| * called during draw stage, you have no access to composition scope, meaning that [Composable] |
| * function invocation inside it will result to runtime exception |
| */ |
| @Composable |
| fun Canvas(modifier: Modifier, onDraw: DrawScope.() -> Unit) = |
| Spacer(modifier.drawBehind(onDraw)) |
| |
| /** |
| * Component that allow you to specify an area on the screen and perform canvas drawing on this |
| * area. You MUST specify size with modifier, whether with exact sizes via [Modifier.size] |
| * modifier, or relative to parent, via [Modifier.fillMaxSize], [ColumnScope.weight], etc. If parent |
| * wraps this child, only exact sizes must be specified. |
| * |
| * @sample androidx.compose.foundation.samples.CanvasPieChartSample |
| * |
| * @param modifier mandatory modifier to specify size strategy for this composable |
| * @param contentDescription text used by accessibility services to describe what this canvas |
| * represents. This should be provided unless the canvas is used for decorative purposes or as |
| * part of a larger entity already described in some other way. This text should be localized, |
| * such as by using [androidx.compose.ui.res.stringResource] |
| * @param onDraw lambda that will be called to perform drawing. Note that this lambda will be |
| * called during draw stage, you have no access to composition scope, meaning that [Composable] |
| * function invocation inside it will result to runtime exception |
| */ |
| @Composable |
| fun Canvas(modifier: Modifier, contentDescription: String, onDraw: DrawScope.() -> Unit) = |
| Spacer(modifier.drawBehind(onDraw).semantics { this.contentDescription = contentDescription }) |
