feat: Add compose element screenshot (#847)

README.md

@@ -202,6 +202,7 @@ In order to change between subdrivers use the [driver](#settings-api) setting. S
 - getPageSource: The returned page source is retrieved from Compose and all elements there contain [Compose-specific](#compose-element-attributes) attributes.
 - click, isDisplayed, isEnabled, clear, getText, sendKeys, getElementRect, getValue, isSelected: These commands should properly support compose elements.
 - getAttribute: Accepts and returns Compose-specific element attributes. See [Compose Element Attributes](#compose-element-attributes) for the full list of supported Compose element attributes.
+- getElementScreenshot: Fetches a screenshot of the given Compose element. Available since driver version *2.14.0*
 
 Calling other driver element-specific APIs not listed above would most likely throw an exception as Compose and Espresso elements are being stored in completely separated internal caches and must not be mixed.
 

espresso-server/app/src/androidTest/java/io/appium/espressoserver/lib/handlers/ElementScreenshot.kt

@@ -16,16 +16,17 @@
 
 package io.appium.espressoserver.lib.handlers
 
-import io.appium.espressoserver.lib.handlers.exceptions.AppiumException
-import io.appium.espressoserver.lib.helpers.ScreenshotsHelper
+import io.appium.espressoserver.lib.helpers.getNodeInteractionById
+import io.appium.espressoserver.lib.helpers.takeComposeNodeScreenshot
+import io.appium.espressoserver.lib.helpers.takeEspressoViewScreenshot
 import io.appium.espressoserver.lib.model.AppiumParams
 import io.appium.espressoserver.lib.model.EspressoElement
 
 class ElementScreenshot : RequestHandler<AppiumParams, String> {
 
-    @Throws(AppiumException::class)
-    override fun handleInternal(params: AppiumParams): String {
-        val view = EspressoElement.getCachedViewStateById(params.elementId).view
-        return ScreenshotsHelper(view).screenshot
-    }
+    override fun handleEspresso(params: AppiumParams): String =
+        takeEspressoViewScreenshot(EspressoElement.getCachedViewStateById(params.elementId).view)
+
+    override fun handleCompose(params: AppiumParams): String =
+        takeComposeNodeScreenshot(getNodeInteractionById(params.elementId!!))
 }

espresso-server/app/src/androidTest/java/io/appium/espressoserver/lib/handlers/ScreenshotHandler.kt

@@ -16,14 +16,9 @@
 
 package io.appium.espressoserver.lib.handlers
 
-import io.appium.espressoserver.lib.handlers.exceptions.AppiumException
-import io.appium.espressoserver.lib.helpers.ScreenshotsHelper
+import io.appium.espressoserver.lib.helpers.takeScreenshot
 import io.appium.espressoserver.lib.model.AppiumParams
 
 class ScreenshotHandler : RequestHandler<AppiumParams, String> {
-
-    @Throws(AppiumException::class)
-    override fun handleInternal(params: AppiumParams): String {
-        return ScreenshotsHelper().screenshot
-    }
+    override fun handleInternal(params: AppiumParams): String = takeScreenshot()
 }

espresso-server/app/src/androidTest/java/io/appium/espressoserver/lib/handlers/exceptions/ScreenCaptureException.kt

@@ -19,7 +19,11 @@ package io.appium.espressoserver.lib.handlers.exceptions
 import fi.iki.elonen.NanoHTTPD
 
 
-class ScreenCaptureException(reason: String) : AppiumException(reason) {
+class ScreenCaptureException : AppiumException {
+    constructor(reason: String) : super(reason)
+
+    constructor(reason: String, e: Throwable) : super(reason, e)
+
     override fun error(): String {
         return "unable to capture screen"
     }

espresso-server/app/src/androidTest/java/io/appium/espressoserver/lib/helpers/ScreenshotHelpers.kt

@@ -0,0 +1,59 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * See the NOTICE file distributed with this work for additional
+ * information regarding copyright ownership.
+ * 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 io.appium.espressoserver.lib.helpers
+
+import android.graphics.Bitmap
+import android.util.Base64
+import android.view.View
+import androidx.compose.ui.graphics.asAndroidBitmap
+import androidx.compose.ui.test.SemanticsNodeInteraction
+import androidx.compose.ui.test.captureToImage
+
+import java.io.ByteArrayOutputStream
+import androidx.test.runner.screenshot.Screenshot
+import io.appium.espressoserver.lib.handlers.exceptions.ScreenCaptureException
+
+private fun encodeBitmap(bitmap: Bitmap?, targetNameSupplier: () -> String): String {
+    if (bitmap == null || bitmap.height == 0 || bitmap.width == 0) {
+        throw ScreenCaptureException("Cannot capture a shot of the ${targetNameSupplier()}. " +
+                "Make sure none of the currently visible " +
+                "views have FLAG_SECURE set and that it is possible to take a screenshot manually")
+    }
+    val outputStream = ByteArrayOutputStream()
+    bitmap.compress(Bitmap.CompressFormat.PNG, 100, outputStream)
+    return Base64.encodeToString(outputStream.toByteArray(), Base64.NO_WRAP)
+}
+
+fun takeScreenshot(): String {
+    return encodeBitmap(Screenshot.capture().bitmap) { "current screen" }
+}
+
+fun takeEspressoViewScreenshot(view: View): String =
+    try {
+        encodeBitmap(Screenshot.capture(view).bitmap) { view.javaClass.name }
+    } catch (e: RuntimeException) {
+        throw ScreenCaptureException("Cannot take a screenshot of a view", e)
+    }
+
+fun takeComposeNodeScreenshot(nodeInteraction: SemanticsNodeInteraction): String =
+    try {
+        encodeBitmap(
+            nodeInteraction.captureToImage().asAndroidBitmap()
+        ) { nodeInteraction.fetchSemanticsNode().toString() }
+    } catch (e: RuntimeException) {
+        throw ScreenCaptureException("Cannot take a screenshot of a node", e)
+    }