Fix #828: Add accessibility API

app/src/main/AndroidManifest.xml

@@ -176,6 +176,19 @@
             android:enabled="true"
             android:exported="false" />
 
+        <service
+            android:name=".TermuxAccessibilityService"
+            android:enabled="true"
+            android:exported="false"
+            android:permission="android.permission.BIND_ACCESSIBILITY_SERVICE">
+            <intent-filter>
+                <action android:name="android.accessibilityservice.AccessibilityService"/>
+            </intent-filter>
+            <meta-data
+                android:name="android.accessibilityservice"
+                android:resource="@xml/accessibility_service_config"/>
+        </service>
+
         <service
             android:name=".apis.JobSchedulerAPI$JobSchedulerService"
             android:permission="android.permission.BIND_JOB_SERVICE"

app/src/main/java/com/termux/api/TermuxAccessibilityService.java

@@ -0,0 +1,26 @@
+package com.termux.api;
+
+import com.termux.shared.logger.Logger;
+
+import android.accessibilityservice.AccessibilityService;
+import android.view.accessibility.AccessibilityEvent;
+
+public class TermuxAccessibilityService extends AccessibilityService {
+
+    private static final String LOG_TAG = "AccessibilityService";
+
+	public static TermuxAccessibilityService instance;
+
+    @Override
+    protected void onServiceConnected() {
+        super.onServiceConnected();
+        Logger.logDebug(LOG_TAG, "onServiceConnected");
+        instance = this;
+    }
+
+    @Override
+    public void onAccessibilityEvent(AccessibilityEvent event) {}
+
+    @Override
+    public void onInterrupt() {}
+}

app/src/main/java/com/termux/api/TermuxApiReceiver.java

@@ -8,6 +8,7 @@
 import android.provider.Settings;
 import android.widget.Toast;
 
+import com.termux.api.apis.AccessibilityAPI;
 import com.termux.api.apis.AudioAPI;
 import com.termux.api.apis.BatteryStatusAPI;
 import com.termux.api.apis.BrightnessAPI;
@@ -84,6 +85,9 @@ private void doWork(Context context, Intent intent) {
         }
 
         switch (apiMethod) {
+            case "Accessibility":
+                AccessibilityAPI.onReceive(this, context, intent);
+                break;
             case "AudioInfo":
                 AudioAPI.onReceive(this, context, intent);
                 break;

app/src/main/java/com/termux/api/apis/AccessibilityAPI.java

@@ -0,0 +1,282 @@
+package com.termux.api.apis;
+
+import android.content.Context;
+import android.content.Intent;
+
+import com.termux.api.TermuxApiReceiver;
+import com.termux.api.util.ResultReturner;
+import com.termux.shared.logger.Logger;
+
+import java.io.PrintWriter;
+
+import com.termux.api.TermuxAccessibilityService;
+import android.view.accessibility.AccessibilityNodeInfo;
+import android.accessibilityservice.GestureDescription;
+import android.graphics.Path;
+
+import javax.xml.parsers.DocumentBuilder;
+import javax.xml.parsers.ParserConfigurationException;
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.transform.Transformer;
+import javax.xml.transform.TransformerFactory;
+import javax.xml.transform.TransformerException;
+import javax.xml.transform.OutputKeys;
+import javax.xml.transform.dom.DOMSource;
+import javax.xml.transform.stream.StreamResult;
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+import java.io.StringWriter;
+
+import android.graphics.Rect;
+
+import android.provider.Settings;
+
+import android.view.accessibility.AccessibilityManager;
+import android.accessibilityservice.AccessibilityServiceInfo;
+import android.content.pm.ServiceInfo;
+import java.util.List;
+import android.accessibilityservice.AccessibilityService;
+import android.os.Bundle;
+
+import android.view.Display;
+import android.accessibilityservice.AccessibilityService.TakeScreenshotCallback;
+import android.accessibilityservice.AccessibilityService.ScreenshotResult;
+import android.hardware.HardwareBuffer;
+import android.graphics.ColorSpace;
+import android.graphics.Bitmap;
+import java.io.OutputStream;
+import java.io.IOException;
+import java.lang.reflect.Field;
+
+public class AccessibilityAPI {
+
+    private static final String LOG_TAG = "AccessibilityAPI";
+
+    public static void onReceive(TermuxApiReceiver apiReceiver, final Context context, Intent intent) {
+        Logger.logDebug(LOG_TAG, "onReceive");
+
+        boolean isAccessibilityEnabled = isAccessibilityServiceEnabled(context, TermuxAccessibilityService.class);
+        if (!isAccessibilityEnabled) {
+            Intent accessibilityIntent = new Intent(Settings.ACTION_ACCESSIBILITY_SETTINGS);
+            accessibilityIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+            context.startActivity(accessibilityIntent);
+        }
+
+		if (intent.hasExtra("dump")) {
+			dump(apiReceiver, intent);
+		} else if (intent.hasExtra("click")) {
+			click(intent.getIntExtra("x", 0), intent.getIntExtra("y", 0), intent.getIntExtra("duration", 1));
+			returnEmptyString(apiReceiver, intent);
+		} else if (intent.hasExtra("type")) {
+			type(intent.getStringExtra("type"));
+			returnEmptyString(apiReceiver, intent);
+		} else if (intent.hasExtra("global-action")) {
+			performGlobalAction(intent.getStringExtra("global-action"));
+			returnEmptyString(apiReceiver, intent);
+		} else if (intent.hasExtra("screenshot")) {
+			screenshot(apiReceiver, context, intent);
+		}
+    }
+
+	// Necessary for void functions not to hang.
+	private static void returnEmptyString(TermuxApiReceiver apiReceiver, Intent intent) {
+		ResultReturner.returnData(apiReceiver, intent, out -> {});
+	}
+
+    // [The Stack Overflow answer 14923144](https://stackoverflow.com/a/14923144)
+    public static boolean isAccessibilityServiceEnabled(Context context, Class<? extends AccessibilityService> service) {
+        AccessibilityManager am = (AccessibilityManager) context.getSystemService(Context.ACCESSIBILITY_SERVICE);
+        List<AccessibilityServiceInfo> enabledServices = am.getEnabledAccessibilityServiceList(AccessibilityServiceInfo.FEEDBACK_ALL_MASK);
+
+        for (AccessibilityServiceInfo enabledService : enabledServices) {
+            ServiceInfo enabledServiceInfo = enabledService.getResolveInfo().serviceInfo;
+            if (enabledServiceInfo.packageName.equals(context.getPackageName()) && enabledServiceInfo.name.equals(service.getName()))
+                return true;
+        }
+
+        return false;
+    }
+
+    private static void click(int x, int y, int millisecondsDuration) {
+        Path swipePath = new Path();
+        swipePath.moveTo(x, y);
+        GestureDescription.Builder gestureBuilder = new GestureDescription.Builder();
+        gestureBuilder.addStroke(new GestureDescription.StrokeDescription(swipePath, 0, millisecondsDuration));
+        TermuxAccessibilityService.instance.dispatchGesture(gestureBuilder.build(), null, null);
+    }
+
+    // The aim of this function is to give a compatible output with `adb` `uiautomator dump`.
+    private static void dump(TermuxApiReceiver apiReceiver, Intent intent) {
+        AccessibilityNodeInfo node = TermuxAccessibilityService.instance.getRootInActiveWindow();
+        // On Signal *App permissions* for instance
+        if (node == null) {
+			ResultReturner.returnData(apiReceiver, intent, out -> {});
+            return;
+        }
+
+		String swString = dumpAuxiliary(node);
+
+		ResultReturner.returnData(apiReceiver, intent, out -> {
+			out.write(swString);
+		});
+    }
+
+	private static String dumpAuxiliary(AccessibilityNodeInfo node) {
+		// Create a DocumentBuilder
+        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
+        DocumentBuilder builder = null;
+        try {
+            builder = factory.newDocumentBuilder();
+        } catch (ParserConfigurationException parserConfigurationException) {
+            Logger.logDebug(LOG_TAG, "ParserConfigurationException");
+        }
+
+        // Create a new Document
+        Document document = builder.newDocument();
+
+        // Create root element
+        Element root = document.createElement("hierarchy");
+        document.appendChild(root);
+
+        dumpNodeAuxiliary(document, root, node);
+
+        // Write as XML
+        TransformerFactory transformerFactory = TransformerFactory.newInstance();
+        Transformer transformer = null;
+        try {
+            transformer = transformerFactory.newTransformer();
+        } catch (TransformerException transformerException) {
+            Logger.logDebug(LOG_TAG, "TransformerException transformerFactory.newTransformer");
+        }
+        transformer.setOutputProperty(OutputKeys.INDENT, "yes");
+        transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2");
+        // Necessary to not have surrogate pairs for emojis, see [Benjamin_Loison/Voice_assistant/issues/83#issue-3661619](https://codeberg.org/Benjamin_Loison/Voice_assistant/issues/83#issue-3661619)
+        transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-16");
+        DOMSource source = new DOMSource(document);
+
+        StringWriter sw = new StringWriter();
+        StreamResult result = new StreamResult(sw);
+        try {
+            transformer.transform(source, result);
+        } catch (TransformerException transformerException) {
+            Logger.logDebug(LOG_TAG, "TransformerException transformer.transform");
+        }
+		return sw.toString();
+	}
+
+    private static void dumpNodeAuxiliary(Document document, Element element, AccessibilityNodeInfo node) {
+        for (int i = 0; i < node.getChildCount(); i++) {
+            AccessibilityNodeInfo nodeChild = node.getChild(i);
+            // May be faced randomly, see [Benjamin-Loison/android/issues/28#issuecomment-3975714760](https://github.com/Benjamin-Loison/android/issues/28#issuecomment-3975714760)
+            if (nodeChild == null)
+            {
+                continue;
+            }
+            Element elementChild = document.createElement("node");
+
+            elementChild.setAttribute("index", String.valueOf(i));
+
+            elementChild.setAttribute("text", getCharSequenceAsString(nodeChild.getText()));
+
+            String nodeChildViewIdResourceName = nodeChild.getViewIdResourceName();
+            elementChild.setAttribute("resource-id", nodeChildViewIdResourceName != null ? nodeChildViewIdResourceName : "");
+
+            elementChild.setAttribute("class", nodeChild.getClassName().toString());
+
+            elementChild.setAttribute("package", nodeChild.getPackageName().toString());
+
+            elementChild.setAttribute("content-desc", getCharSequenceAsString(nodeChild.getContentDescription()));
+
+            elementChild.setAttribute("checkable", String.valueOf(nodeChild.isCheckable()));
+
+            elementChild.setAttribute("checked", String.valueOf(nodeChild.isChecked()));
+
+            elementChild.setAttribute("clickable", String.valueOf(nodeChild.isClickable()));
+
+            elementChild.setAttribute("enabled", String.valueOf(nodeChild.isEnabled()));
+
+            elementChild.setAttribute("focusable", String.valueOf(nodeChild.isFocusable()));
+
+            elementChild.setAttribute("focused", String.valueOf(nodeChild.isFocused()));
+
+            elementChild.setAttribute("scrollable", String.valueOf(nodeChild.isScrollable()));
+
+            elementChild.setAttribute("long-clickable", String.valueOf(nodeChild.isLongClickable()));
+
+            elementChild.setAttribute("password", String.valueOf(nodeChild.isPassword()));
+
+            elementChild.setAttribute("selected", String.valueOf(nodeChild.isSelected()));
+
+            Rect nodeChildBounds = new Rect();
+            nodeChild.getBoundsInScreen(nodeChildBounds);
+            elementChild.setAttribute("bounds", nodeChildBounds.toShortString());
+
+            elementChild.setAttribute("drawing-order", String.valueOf(nodeChild.getDrawingOrder()));
+
+            elementChild.setAttribute("hint", getCharSequenceAsString(nodeChild.getHintText()));
+
+            element.appendChild(elementChild);
+            dumpNodeAuxiliary(document, elementChild, nodeChild);
+        }
+    }
+
+    private static String getCharSequenceAsString(CharSequence charSequence) {
+        return charSequence != null ? charSequence.toString() : "";
+    }
+
+    private static void type(String toType) {
+        AccessibilityNodeInfo focusedNode = TermuxAccessibilityService.instance.getRootInActiveWindow().findFocus(AccessibilityNodeInfo.FOCUS_INPUT);
+        Bundle arguments = new Bundle();
+        arguments.putCharSequence(AccessibilityNodeInfo.ACTION_ARGUMENT_SET_TEXT_CHARSEQUENCE, toType);
+        focusedNode.performAction(AccessibilityNodeInfo.ACTION_SET_TEXT, arguments);
+    }
+
+    private static void performGlobalAction(String globalActionString) {
+		String fieldName = "GLOBAL_ACTION_" + globalActionString.toUpperCase();
+		Field field = null;
+		try {
+			field = AccessibilityService.class.getDeclaredField(fieldName);
+		} catch (NoSuchFieldException noSuchFieldException) {
+			Logger.logDebug(LOG_TAG, "NoSuchFieldException");
+		}
+		Object globalActionObject = null;
+		try {
+			globalActionObject = field.get(null);
+		} catch(IllegalAccessException illegalAccessException) {
+			Logger.logDebug(LOG_TAG, "IllegalAccessException");
+		}
+		int globalActionInt = (int)globalActionObject;
+        TermuxAccessibilityService.instance.performGlobalAction(globalActionInt);
+    }
+
+	private static void screenshot(TermuxApiReceiver apiReceiver, final Context context, Intent intent) {
+		TermuxAccessibilityService.instance.takeScreenshot(
+            Display.DEFAULT_DISPLAY,
+            context.getMainExecutor(),
+            new TakeScreenshotCallback() {
+
+                @Override
+                public void onSuccess(ScreenshotResult screenshotResult) {
+                    Logger.logDebug(LOG_TAG, "onSuccess");
+                    HardwareBuffer buffer = screenshotResult.getHardwareBuffer();
+                    ColorSpace colorSpace = screenshotResult.getColorSpace();
+
+                    Bitmap bitmap = Bitmap.wrapHardwareBuffer(buffer, colorSpace);
+
+                    ResultReturner.returnData(apiReceiver, intent, new ResultReturner.BinaryOutput()
+                    {
+                        @Override
+                        public void writeResult(OutputStream out) throws IOException {
+                            bitmap.compress(Bitmap.CompressFormat.PNG, 100, out);
+                        }
+                    });
+                }
+
+                @Override
+                public void onFailure(int errorCode) {
+                    Logger.logDebug(LOG_TAG, "onFailure: " + errorCode);
+                }
+            }
+        );
+	}
+}

app/src/main/res/xml/accessibility_service_config.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<accessibility-service
+	xmlns:android="http://schemas.android.com/apk/res/android"
+	android:canRetrieveWindowContent="true"
+	android:accessibilityFlags="flagReportViewIds|flagIncludeNotImportantViews"
+	android:canPerformGestures="true"
+	android:canTakeScreenshot="true"/>