Add Picasso#rememberPainter extension function under new :picasso-compose module

Author: gamepro65

build.gradle

@@ -5,7 +5,7 @@ buildscript {
     'targetSdk': 31,
     'sourceCompatibility': JavaVersion.VERSION_1_8,
     'targetCompatibility': JavaVersion.VERSION_1_8,
-    'kotlin': '1.5.21',
+    'kotlin': '1.6.10',
     'okhttp': '4.9.3',
     'okio': '3.0.0',
   ]
@@ -28,6 +28,9 @@ buildscript {
     truth: 'com.google.truth:truth:1.1.3',
     robolectric: 'org.robolectric:robolectric:4.6.1',
     mockito: 'org.mockito:mockito-core:3.0.0',
+    drawablePainter: 'com.google.accompanist:accompanist-drawablepainter:0.23.1',
+    composeUi: 'androidx.compose.ui:ui:1.1.1',
+    foundation: 'androidx.compose.foundation:foundation:1.1.1'
   ]
 
   ext.isCi = "true" == System.getenv('CI')

picasso-compose/README.md

@@ -0,0 +1,16 @@
+Picasso Compose Ui
+====================================
+
+A [Painter] which wraps a [RequestCreator]
+
+Usage
+-----
+
+Create a `Painter` using the rememberPainter extension on a Picasso instance.
+
+```kotlin
+val picasso = Picasso.Builder(context).build()
+val painter = picasso.rememberPainter(key = url) {
+  it.load(url).placeholder(placeholderDrawable).error(errorDrawable)
+}
+```

picasso-compose/api/picasso-compose.api

@@ -0,0 +1,4 @@
+public final class com/squareup/picasso3/compose/PicassoPainterKt {
+	public static final fun rememberPainter (Lcom/squareup/picasso3/Picasso;Ljava/lang/Object;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;Landroidx/compose/runtime/Composer;II)Landroidx/compose/ui/graphics/painter/Painter;
+}
+

picasso-compose/build.gradle

@@ -0,0 +1,40 @@
+apply plugin: 'com.android.library'
+apply plugin: 'org.jetbrains.kotlin.android'
+apply plugin: 'com.vanniktech.maven.publish'
+
+android {
+  compileSdkVersion versions.compileSdk
+
+  defaultConfig {
+    minSdkVersion versions.minSdk
+  }
+
+  buildFeatures {
+    compose true
+  }
+
+  composeOptions {
+    kotlinCompilerExtensionVersion "1.1.1"
+  }
+
+  compileOptions {
+    sourceCompatibility versions.sourceCompatibility
+    targetCompatibility versions.targetCompatibility
+  }
+
+  lintOptions {
+    textOutput 'stdout'
+    textReport true
+    lintConfig rootProject.file('lint.xml')
+  }
+}
+
+dependencies {
+  api project(':picasso')
+
+  implementation deps.drawablePainter
+  implementation deps.composeUi
+  implementation deps.foundation
+
+  compileOnly deps.androidxAnnotations
+}

picasso-compose/gradle.properties

@@ -0,0 +1,4 @@
+POM_ARTIFACT_ID=picasso-compose
+POM_NAME=Picasso Compose
+POM_DESCRIPTION=Compose UI support for Picasso.
+POM_PACKAGING=aar

picasso-compose/src/main/AndroidManifest.xml

@@ -0,0 +1 @@
+<manifest package="com.squareup.picasso3.compose" />

picasso-compose/src/main/java/com/squareup/picasso3/compose/PicassoPainter.kt

@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2022 Square, 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.
+ */
+package com.squareup.picasso3.compose
+
+import android.graphics.drawable.Drawable
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.RememberObserver
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.geometry.Size
+import androidx.compose.ui.graphics.ColorFilter
+import androidx.compose.ui.graphics.DefaultAlpha
+import androidx.compose.ui.graphics.drawscope.DrawScope
+import androidx.compose.ui.graphics.painter.Painter
+import com.google.accompanist.drawablepainter.DrawablePainter
+import com.squareup.picasso3.DrawableTarget
+import com.squareup.picasso3.Picasso
+import com.squareup.picasso3.Picasso.LoadedFrom
+import com.squareup.picasso3.RequestCreator
+
+@Composable
+fun Picasso.rememberPainter(
+  key: Any? = null,
+  onError: ((Exception) -> Unit)? = null,
+  request: (Picasso) -> RequestCreator,
+): Painter {
+  return remember(key) { PicassoPainter(this, request, onError) }
+}
+
+internal class PicassoPainter(
+  private val picasso: Picasso,
+  private val request: (Picasso) -> RequestCreator,
+  private val onError: ((Exception) -> Unit)? = null
+) : Painter(), RememberObserver, DrawableTarget {
+
+  private var painter: Painter by mutableStateOf(EmptyPainter)
+  private var alpha: Float by mutableStateOf(DefaultAlpha)
+  private var colorFilter: ColorFilter? by mutableStateOf(null)
+
+  override val intrinsicSize: Size
+    get() = painter.intrinsicSize
+
+  override fun applyAlpha(alpha: Float): Boolean {
+    this.alpha = alpha
+    return true
+  }
+
+  override fun applyColorFilter(colorFilter: ColorFilter?): Boolean {
+    this.colorFilter = colorFilter
+    return true
+  }
+
+  override fun DrawScope.onDraw() {
+    with(painter) {
+      draw(size, alpha, colorFilter)
+    }
+  }
+
+  override fun onRemembered() {
+    request.invoke(picasso).into(this)
+  }
+
+  override fun onAbandoned() {
+    (painter as? RememberObserver)?.onAbandoned()
+    painter = EmptyPainter
+    picasso.cancelRequest(this)
+  }
+
+  override fun onForgotten() {
+    (painter as? RememberObserver)?.onForgotten()
+    painter = EmptyPainter
+    picasso.cancelRequest(this)
+  }
+
+  override fun onPrepareLoad(placeHolderDrawable: Drawable?) {
+    placeHolderDrawable?.let(::setPainter)
+  }
+
+  override fun onDrawableLoaded(drawable: Drawable, from: LoadedFrom) {
+    setPainter(drawable)
+  }
+
+  override fun onDrawableFailed(e: Exception, errorDrawable: Drawable?) {
+    onError?.invoke(e)
+    errorDrawable?.let(::setPainter)
+  }
+
+  private fun setPainter(drawable: Drawable) {
+    (painter as? RememberObserver)?.onForgotten()
+    painter = DrawablePainter(drawable).apply(DrawablePainter::onRemembered)
+  }
+}
+
+private object EmptyPainter : Painter() {
+  override val intrinsicSize = Size.Zero
+  override fun DrawScope.onDraw() = Unit
+}

picasso-sample/build.gradle

@@ -10,6 +10,14 @@ android {
     applicationId 'com.example.picasso'
   }
 
+  buildFeatures {
+    compose true
+  }
+
+  composeOptions {
+    kotlinCompilerExtensionVersion "1.1.1"
+  }
+
   compileOptions {
     sourceCompatibility versions.sourceCompatibility
     targetCompatibility versions.targetCompatibility
@@ -32,6 +40,11 @@ dependencies {
   implementation deps.androidxFragment
   implementation deps.androidxStartup
 
+  implementation deps.drawablePainter
+  implementation deps.composeUi
+  implementation deps.foundation
+
   implementation project(':picasso')
   implementation project(':picasso-stats')
+  implementation project(':picasso-compose')
 }

picasso-sample/src/main/AndroidManifest.xml

@@ -34,6 +34,7 @@
       </intent-filter>
     </activity>
 
+    <activity android:name=".SampleComposeActivity"/>
     <activity android:name=".SampleContactsActivity"/>
     <activity android:name=".SampleGalleryActivity"/>
     <activity android:name=".SampleListDetailActivity"/>

picasso-sample/src/main/java/com/example/picasso/PicassoSampleAdapter.kt

@@ -38,6 +38,7 @@ internal class PicassoSampleAdapter(context: Context?) : BaseAdapter() {
     private val activityClass: Class<out Activity>?
   ) {
     GRID_VIEW("Image Grid View", SampleGridViewActivity::class.java),
+    COMPOSE_UI("Compose UI", SampleComposeActivity::class.java),
     GALLERY("Load from Gallery", SampleGalleryActivity::class.java),
     CONTACTS("Contact Photos", SampleContactsActivity::class.java),
     LIST_DETAIL("List / Detail View", SampleListDetailActivity::class.java),