Add basic camera support to the android device

driver/sensor/camera.go

@@ -0,0 +1,17 @@
+package sensor
+
+import (
+	"image"
+)
+
+// A camera device is a device that has hardware support for taking photos.
+//
+// Since: 2.7
+type CameraDevice interface {
+	// CapturePhoto opens a native photo capture view that allows the user to optionally
+	// take a photograph.  It returns the image, a boolean to indicate if an image was
+	// taken, and any errors.
+	//
+	// Since: 2.7
+	CapturePhoto() (image.Image, bool, error)
+}

internal/driver/mobile/app/GoNativeActivity.java

@@ -1,5 +1,8 @@
 package org.golang.app;
 
+import java.util.Base64;
+import java.io.ByteArrayOutputStream;
+import java.nio.ByteBuffer;
 import android.app.Activity;
 import android.app.NativeActivity;
 import android.content.Context;
@@ -8,9 +11,12 @@
 import android.content.pm.PackageManager;
 import android.content.res.Configuration;
 import android.graphics.Rect;
+import android.graphics.Bitmap;
+import android.graphics.Bitmap.CompressFormat;
 import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
+import android.provider.MediaStore;
 import android.text.Editable;
 import android.text.InputType;
 import android.text.TextWatcher;
@@ -29,39 +35,41 @@
 import android.widget.TextView.OnEditorActionListener;
 
 public class GoNativeActivity extends NativeActivity {
-	private static GoNativeActivity goNativeActivity;
-	private static final int FILE_OPEN_CODE = 1;
-	private static final int FILE_SAVE_CODE = 2;
+    private static GoNativeActivity goNativeActivity;
+    private static final int FILE_OPEN_CODE = 1;
+    private static final int FILE_SAVE_CODE = 2;
+    private static final int CAMERA_OPEN_CODE = 3;
 
-	private static final int DEFAULT_INPUT_TYPE = InputType.TYPE_TEXT_FLAG_NO_SUGGESTIONS;
+    private static final int DEFAULT_INPUT_TYPE = InputType.TYPE_TEXT_FLAG_NO_SUGGESTIONS;
 
-	private static final int DEFAULT_KEYBOARD_CODE = 0;
-	private static final int SINGLELINE_KEYBOARD_CODE = 1;
-	private static final int NUMBER_KEYBOARD_CODE = 2;
-	private static final int PASSWORD_KEYBOARD_CODE = 3;
+    private static final int DEFAULT_KEYBOARD_CODE = 0;
+    private static final int SINGLELINE_KEYBOARD_CODE = 1;
+    private static final int NUMBER_KEYBOARD_CODE = 2;
+    private static final int PASSWORD_KEYBOARD_CODE = 3;
 
     private native void filePickerReturned(String str);
+    private native void capturePhotoReturned(String str);
     private native void insetsChanged(int top, int bottom, int left, int right);
     private native void keyboardTyped(String str);
     private native void keyboardDelete();
     private native void backPressed();
     private native void setDarkMode(boolean dark);
 
-	private EditText mTextEdit;
-	private boolean ignoreKey = false;
-	private boolean keyboardUp = false;
+    private EditText mTextEdit;
+    private boolean ignoreKey = false;
+    private boolean keyboardUp = false;
 
-	public GoNativeActivity() {
-		super();
-		goNativeActivity = this;
-	}
+    public GoNativeActivity() {
+        super();
+        goNativeActivity = this;
+    }
 
-	String getTmpdir() {
-		return getCacheDir().getAbsolutePath();
-	}
+    String getTmpdir() {
+        return getCacheDir().getAbsolutePath();
+    }
 
-	void updateLayout() {
-	    try {
+    void updateLayout() {
+        try {
             WindowInsets insets = getWindow().getDecorView().getRootWindowInsets();
             if (insets == null) {
                 return;
@@ -70,7 +78,7 @@ void updateLayout() {
             insetsChanged(insets.getSystemWindowInsetTop(), insets.getSystemWindowInsetBottom(),
                 insets.getSystemWindowInsetLeft(), insets.getSystemWindowInsetRight());
         } catch (java.lang.NoSuchMethodError e) {
-    	    Rect insets = new Rect();
+            Rect insets = new Rect();
             getWindow().getDecorView().getWindowVisibleDisplayFrame(insets);
 
             View view = findViewById(android.R.id.content).getRootView();
@@ -179,6 +187,15 @@ void doShowFileOpen(String mimes) {
         startActivityForResult(Intent.createChooser(intent, "Open File"), FILE_OPEN_CODE);
     }
 
+    static void showCameraOpen() {
+        goNativeActivity.doShowCameraOpen();
+    }
+
+    void doShowCameraOpen() {
+        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
+        startActivityForResult(intent, CAMERA_OPEN_CODE);
+    }
+
     static void showFileSave(String mimes, String filename) {
         goNativeActivity.doShowFileSave(mimes, filename);
     }
@@ -195,58 +212,58 @@ void doShowFileSave(String mimes, String filename) {
         intent.addCategory(Intent.CATEGORY_OPENABLE);
         startActivityForResult(Intent.createChooser(intent, "Save File"), FILE_SAVE_CODE);
     }
-	static int getRune(int deviceId, int keyCode, int metaState) {
-		try {
-			int rune = KeyCharacterMap.load(deviceId).get(keyCode, metaState);
-			if (rune == 0) {
-				return -1;
-			}
-			return rune;
-		} catch (KeyCharacterMap.UnavailableException e) {
-			return -1;
-		} catch (Exception e) {
-			Log.e("Fyne", "exception reading KeyCharacterMap", e);
-			return -1;
-		}
-	}
+    static int getRune(int deviceId, int keyCode, int metaState) {
+        try {
+            int rune = KeyCharacterMap.load(deviceId).get(keyCode, metaState);
+            if (rune == 0) {
+                return -1;
+            }
+            return rune;
+        } catch (KeyCharacterMap.UnavailableException e) {
+            return -1;
+        } catch (Exception e) {
+            Log.e("Fyne", "exception reading KeyCharacterMap", e);
+            return -1;
+        }
+    }
 
-	private void load() {
-		// Interestingly, NativeActivity uses a different method
-		// to find native code to execute, avoiding
-		// System.loadLibrary. The result is Java methods
-		// implemented in C with JNIEXPORT (and JNI_OnLoad) are not
-		// available unless an explicit call to System.loadLibrary
-		// is done. So we do it here, borrowing the name of the
-		// library from the same AndroidManifest.xml metadata used
-		// by NativeActivity.
-		try {
-			ActivityInfo ai = getPackageManager().getActivityInfo(
-					getIntent().getComponent(), PackageManager.GET_META_DATA);
-			if (ai.metaData == null) {
-				Log.e("Fyne", "loadLibrary: no manifest metadata found");
-				return;
-			}
-			String libName = ai.metaData.getString("android.app.lib_name");
-			System.loadLibrary(libName);
-		} catch (Exception e) {
-			Log.e("Fyne", "loadLibrary failed", e);
-		}
-	}
+    private void load() {
+        // Interestingly, NativeActivity uses a different method
+        // to find native code to execute, avoiding
+        // System.loadLibrary. The result is Java methods
+        // implemented in C with JNIEXPORT (and JNI_OnLoad) are not
+        // available unless an explicit call to System.loadLibrary
+        // is done. So we do it here, borrowing the name of the
+        // library from the same AndroidManifest.xml metadata used
+        // by NativeActivity.
+        try {
+            ActivityInfo ai = getPackageManager().getActivityInfo(
+                    getIntent().getComponent(), PackageManager.GET_META_DATA);
+            if (ai.metaData == null) {
+                Log.e("Fyne", "loadLibrary: no manifest metadata found");
+                return;
+            }
+            String libName = ai.metaData.getString("android.app.lib_name");
+            System.loadLibrary(libName);
+        } catch (Exception e) {
+            Log.e("Fyne", "loadLibrary failed", e);
+        }
+    }
+
+    @Override
+    public void onCreate(Bundle savedInstanceState) {
+        load();
+        super.onCreate(savedInstanceState);
+        setupEntry();
+        updateTheme(getResources().getConfiguration());
 
-	@Override
-	public void onCreate(Bundle savedInstanceState) {
-		load();
-		super.onCreate(savedInstanceState);
-		setupEntry();
-		updateTheme(getResources().getConfiguration());
-
-		View view = findViewById(android.R.id.content).getRootView();
-		view.addOnLayoutChangeListener(new View.OnLayoutChangeListener() {
-			public void onLayoutChange (View v, int left, int top, int right, int bottom,
-			                            int oldLeft, int oldTop, int oldRight, int oldBottom) {
-				GoNativeActivity.this.updateLayout();
-			}
-		});
+        View view = findViewById(android.R.id.content).getRootView();
+        view.addOnLayoutChangeListener(new View.OnLayoutChangeListener() {
+            public void onLayoutChange (View v, int left, int top, int right, int bottom,
+                                        int oldLeft, int oldTop, int oldRight, int oldBottom) {
+                GoNativeActivity.this.updateLayout();
+            }
+        });
     }
 
     private void setupEntry() {
@@ -304,23 +321,40 @@ public void afterTextChanged(Editable s) {
                 });
             }
         });
-	}
+    }
 
-	@Override
+    @Override
     protected void onActivityResult(int requestCode, int resultCode, Intent data) {
         // unhandled request
-        if (requestCode != FILE_OPEN_CODE && requestCode != FILE_SAVE_CODE) {
+        if (requestCode != FILE_OPEN_CODE && requestCode != FILE_SAVE_CODE && requestCode != CAMERA_OPEN_CODE) {
             return;
         }
 
-        // dialog was cancelled
-        if (resultCode != Activity.RESULT_OK) {
-            filePickerReturned("");
-            return;
-        }
+        if (requestCode == CAMERA_OPEN_CODE) {
+            if (resultCode != Activity.RESULT_OK) {
+                // dialog was cancelled
+                capturePhotoReturned("");
+                return;
+            }
+
+            Bitmap photo = (Bitmap)data.getExtras().get("data");
+
+            ByteArrayOutputStream out = new ByteArrayOutputStream();
+            photo.compress(CompressFormat.JPEG, 90, out);
 
-        Uri uri = data.getData();
-        filePickerReturned(uri.toString());
+            String dataAsString = Base64.getEncoder().encodeToString(out.toByteArray());
+
+            capturePhotoReturned(dataAsString);
+        } else {
+            if (resultCode != Activity.RESULT_OK) {
+                // dialog was cancelled
+                filePickerReturned("");
+                return;
+            }
+
+            Uri uri = data.getData();
+            filePickerReturned(uri.toString());
+	}
     }
 
     @Override

internal/driver/mobile/app/android.c

@@ -53,6 +53,7 @@ static jmethodID show_keyboard_method;
 static jmethodID hide_keyboard_method;
 static jmethodID show_file_open_method;
 static jmethodID show_file_save_method;
+static jmethodID show_camera_open_method;
 static jmethodID finish_method;
 
 jint JNI_OnLoad(JavaVM* vm, void* reserved) {
@@ -95,6 +96,7 @@ void ANativeActivity_onCreate(ANativeActivity *activity, void* savedState, size_
 		show_keyboard_method = find_static_method(env, current_class, "showKeyboard", "(I)V");
 		hide_keyboard_method = find_static_method(env, current_class, "hideKeyboard", "()V");
 		show_file_open_method = find_static_method(env, current_class, "showFileOpen", "(Ljava/lang/String;)V");
+		show_camera_open_method = find_static_method(env, current_class, "showCameraOpen", "()V");
 		show_file_save_method = find_static_method(env, current_class, "showFileSave", "(Ljava/lang/String;Ljava/lang/String;)V");
 		finish_method = find_method(env, current_class, "finishActivity", "()V");
 
@@ -280,11 +282,25 @@ void showFileSave(JNIEnv* env, char* mimes, char* filename) {
 	);
 }
 
+void showCameraOpen(JNIEnv* env) {
+    jstring f = (*env)->NewStringUTF(env, " ");
+    (*env)->CallStaticVoidMethod(
+		env,
+		current_class,
+		show_camera_open_method
+	);
+}
+
 void Java_org_golang_app_GoNativeActivity_filePickerReturned(JNIEnv *env, jclass clazz, jstring str) {
     const char* cstr = (*env)->GetStringUTFChars(env, str, JNI_FALSE);
 	filePickerReturned((char*)cstr);
 }
 
+void Java_org_golang_app_GoNativeActivity_capturePhotoReturned(JNIEnv *env, jclass clazz, jstring str) {
+    const char* cstr = (*env)->GetStringUTFChars(env, str, JNI_FALSE);
+	capturePhotoReturned((char*)cstr);
+}
+
 void Java_org_golang_app_GoNativeActivity_insetsChanged(JNIEnv *env, jclass clazz, int top, int bottom, int left, int right) {
     insetsChanged(top, bottom, left, right);
 }

internal/driver/mobile/app/android.go

@@ -47,9 +47,11 @@ void showKeyboard(JNIEnv* env, int keyboardType);
 void hideKeyboard(JNIEnv* env);
 void showFileOpen(JNIEnv* env, char* mimes);
 void showFileSave(JNIEnv* env, char* mimes, char* filename);
+void showCameraOpen(JNIEnv* env);
 void finish(JNIEnv* env, jobject ctx);
 
 void Java_org_golang_app_GoNativeActivity_filePickerReturned(JNIEnv *env, jclass clazz, jstring str);
+void Java_org_golang_app_GoNativeActivity_capturePhotoReturned(JNIEnv *env, jclass clazz, jstring str);
 */
 import "C"
 
@@ -350,6 +352,18 @@ func filePickerReturned(str *C.char) {
 	fileCallback = nil
 }
 
+var capturePhotoCallback func(string)
+
+//export capturePhotoReturned
+func capturePhotoReturned(str *C.char) {
+	if capturePhotoCallback == nil {
+		return
+	}
+
+	capturePhotoCallback(C.GoString(str))
+	capturePhotoCallback = nil
+}
+
 //export insetsChanged
 func insetsChanged(top, bottom, left, right int) {
 	currentSize.InsetTopPx = top
@@ -425,6 +439,20 @@ func driverShowFileSavePicker(callback func(string, func()), filter *FileFilter,
 	}
 }
 
+func NativeCapturePhoto(callback func(string)) {
+	capturePhotoCallback = callback
+
+	save := func(vm, jniEnv, ctx uintptr) error {
+		env := (*C.JNIEnv)(unsafe.Pointer(jniEnv)) // not a Go heap pointer
+		C.showCameraOpen(env)
+		return nil
+	}
+
+	if err := mobileinit.RunOnJVM(save); err != nil {
+		log.Fatalf("app: %v", err)
+	}
+}
+
 var mainUserFn func(App)
 
 var DisplayMetrics struct {