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riggarooriggaroo
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Merge pull request #16 from android/feature/image-snippets
Add image snippets
2 parents 2f5fab1 + fc5f02a commit 45684d1

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lines changed

11 files changed

+641
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lines changed

‎compose/snippets/build.gradle

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@@ -49,7 +49,7 @@ android {
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dependencies {
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def composeBom = platform('androidx.compose:compose-bom:2022.11.00')
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implementation(composeBom)
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implementation("io.coil-kt:coil-compose:2.2.2")
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implementation 'androidx.core:core-ktx:1.9.0'
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implementation 'androidx.lifecycle:lifecycle-runtime-ktx:2.5.1'
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implementation 'androidx.activity:activity-compose:1.6.1'

‎compose/snippets/src/main/java/com/example/compose/snippets/SnippetsActivity.kt

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@@ -16,11 +16,15 @@ package com.example.compose.snippets
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import android.os.Bundle
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import androidx.activity.ComponentActivity
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import androidx.activity.compose.setContent
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import androidx.compose.foundation.layout.Column
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import androidx.compose.foundation.layout.fillMaxSize
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import androidx.compose.foundation.rememberScrollState
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import androidx.compose.foundation.verticalScroll
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import androidx.compose.material3.MaterialTheme
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import androidx.compose.material3.Surface
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import androidx.compose.ui.Modifier
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import com.example.compose.snippets.graphics.BrushExamplesScreen
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import com.example.compose.snippets.images.ImageExamplesScreen
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import com.example.compose.snippets.ui.theme.SnippetsTheme
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class SnippetsActivity : ComponentActivity() {
@@ -33,7 +37,12 @@ class SnippetsActivity : ComponentActivity() {
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modifier = Modifier.fillMaxSize(),
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color = MaterialTheme.colorScheme.background
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) {
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BrushExamplesScreen()
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// TODO - We should put these in different navigation destinations
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Column(modifier = Modifier
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.fillMaxSize()) {
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// BrushExamplesScreen()
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ImageExamplesScreen()
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}
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}
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}
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}

‎compose/snippets/src/main/java/com/example/compose/snippets/images/CustomPainterSnippets.kt

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@@ -0,0 +1,132 @@
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package com.example.compose.snippets.images
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import androidx.compose.foundation.Image
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import androidx.compose.foundation.background
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import androidx.compose.foundation.layout.Box
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import androidx.compose.foundation.layout.padding
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import androidx.compose.foundation.layout.wrapContentSize
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import androidx.compose.runtime.Composable
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import androidx.compose.runtime.remember
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import androidx.compose.ui.Modifier
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import androidx.compose.ui.draw.paint
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import androidx.compose.ui.geometry.Size
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import androidx.compose.ui.graphics.BlendMode
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import androidx.compose.ui.graphics.Color
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import androidx.compose.ui.graphics.ImageBitmap
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import androidx.compose.ui.graphics.drawscope.DrawScope
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import androidx.compose.ui.graphics.painter.Painter
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import androidx.compose.ui.layout.ContentScale
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import androidx.compose.ui.res.imageResource
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import androidx.compose.ui.res.stringResource
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import androidx.compose.ui.tooling.preview.Preview
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import androidx.compose.ui.unit.IntOffset
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import androidx.compose.ui.unit.IntSize
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import androidx.compose.ui.unit.dp
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import androidx.compose.ui.unit.toSize
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import com.example.compose.snippets.R
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import kotlin.math.roundToInt
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/*
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* Copyright 2022 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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@Preview
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@Composable
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fun CustomPainterUsage() {
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// [START android_compose_images_custom_painter_usage]
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val rainbowImage = ImageBitmap.imageResource(id = R.drawable.rainbow)
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val dogImage = ImageBitmap.imageResource(id = R.drawable.dog)
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val customPainter = remember {
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OverlayImagePainter(dogImage, rainbowImage)
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}
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Image(
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painter = customPainter,
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contentDescription = stringResource(id = R.string.dog_content_description),
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contentScale = ContentScale.Crop,
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modifier = Modifier.wrapContentSize()
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)
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// [END android_compose_images_custom_painter_usage]
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}
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// [START android_compose_images_custom_painter]
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class OverlayImagePainter constructor(
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private val image: ImageBitmap,
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private val imageOverlay: ImageBitmap,
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private val srcOffset: IntOffset = IntOffset.Zero,
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private val srcSize: IntSize = IntSize(image.width, image.height),
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private val overlaySize: IntSize = IntSize(imageOverlay.width, imageOverlay.height)
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) : Painter() {
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private val size: IntSize = validateSize(srcOffset, srcSize)
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override fun DrawScope.onDraw() {
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// draw the first image without any blend mode
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drawImage(
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image,
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srcOffset,
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srcSize,
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dstSize = IntSize(
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this@onDraw.size.width.roundToInt(),
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this@onDraw.size.height.roundToInt()
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)
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)
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// draw the second image with an Overlay blend mode to blend the two together
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drawImage(
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imageOverlay,
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srcOffset,
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overlaySize,
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dstSize = IntSize(
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this@onDraw.size.width.roundToInt(),
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this@onDraw.size.height.roundToInt()
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),
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blendMode = BlendMode.Overlay
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)
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}
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/**
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* Return the dimension of the underlying [ImageBitmap] as it's intrinsic width and height
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*/
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override val intrinsicSize: Size get() = size.toSize()
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private fun validateSize(srcOffset: IntOffset, srcSize: IntSize): IntSize {
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require(
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srcOffset.x >= 0 &&
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srcOffset.y >= 0 &&
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srcSize.width >= 0 &&
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srcSize.height >= 0 &&
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srcSize.width <= image.width &&
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srcSize.height <= image.height
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)
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return srcSize
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}
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}
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// [END android_compose_images_custom_painter]
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@Preview
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@Composable
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fun CustomPainterModifier() {
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// [START android_compose_custom_painter_modifier]
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val rainbowImage = ImageBitmap.imageResource(id = R.drawable.rainbow)
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val dogImage = ImageBitmap.imageResource(id = R.drawable.dog)
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val customPainter = remember {
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OverlayImagePainter(dogImage, rainbowImage)
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}
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Box(
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modifier =
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Modifier.background(color = Color.Gray)
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.padding(30.dp)
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.background(color = Color.Yellow)
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.paint(customPainter)
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) { /** intentionally empty **/ }
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// [END android_compose_custom_painter_modifier]
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}

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