cmd/ebitenmobile: Add Android

Updates #863

cmd/ebitenmobile/gobind.go

@@ -67,7 +67,7 @@ func run() error {
 	prefixUpper := strings.Title(*prefix) + strings.Title(pkgs[0].Name)
 
 	writeFile := func(filename string, content string) error {
-		if err := ioutil.WriteFile(filepath.Join(*outdir, "src", "gobind", filename), []byte(content), 0644); err != nil {
+		if err := ioutil.WriteFile(filepath.Join(*outdir, filename), []byte(content), 0644); err != nil {
 			return err
 		}
 		return nil
@@ -75,6 +75,7 @@ func run() error {
 	replacePrefixes := func(content string) string {
 		content = strings.ReplaceAll(content, "{{.PrefixUpper}}", prefixUpper)
 		content = strings.ReplaceAll(content, "{{.PrefixLower}}", prefixLower)
+		content = strings.ReplaceAll(content, "{{.JavaPkg}}", *javaPkg)
 		return content
 	}
 
@@ -84,12 +85,19 @@ func run() error {
 		switch lang {
 		case "objc":
 			// iOS
-			if err := writeFile(prefixLower+"ebitenviewcontroller_ios.m", replacePrefixes(objcM)); err != nil {
+			if err := writeFile(filepath.Join("src", "gobind", prefixLower+"ebitenviewcontroller_ios.m"), replacePrefixes(objcM)); err != nil {
 				return err
 			}
 		case "java":
 			// Android
-			// TODO: Insert a Java file and let the original gobind compile it.
+			dir := filepath.Join(strings.Split(*javaPkg, ".")...)
+			dir = filepath.Join(dir, prefixLower)
+			if err := writeFile(filepath.Join("java", dir, "EbitenView.java"), replacePrefixes(viewJava)); err != nil {
+				return err
+			}
+			if err := writeFile(filepath.Join("java", dir, "EbitenSurfaceView.java"), replacePrefixes(surfaceViewJava)); err != nil {
+				return err
+			}
 		case "go":
 			// Do nothing.
 		default:
@@ -197,3 +205,168 @@ const objcM = `// Code generated by ebitenmobile. DO NOT EDIT.
 
 @end
 `
+
+const viewJava = `// Code generated by ebitenmobile. DO NOT EDIT.
+
+package {{.JavaPkg}}.{{.PrefixLower}};
+
+import android.content.Context;
+import android.util.AttributeSet;
+import android.view.ViewGroup;
+
+import {{.JavaPkg}}.ebitenmobileview.Ebitenmobileview;
+import {{.JavaPkg}}.ebitenmobileview.ViewRectSetter;
+
+public class EbitenView extends ViewGroup {
+    private double getDeviceScale() {
+        if (deviceScale_ == 0.0) {
+            deviceScale_ = getResources().getDisplayMetrics().density;
+        }
+        return deviceScale_;
+    }
+
+    private double pxToDp(double x) {
+        return x / getDeviceScale();
+    }
+
+    private double dpToPx(double x) {
+        return x * getDeviceScale();
+    }
+
+    private double deviceScale_ = 0.0;
+
+    public EbitenView(Context context) {
+        super(context);
+        ebitenSurfaceView_ = new EbitenSurfaceView(context);
+    }
+
+    public EbitenView(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        ebitenSurfaceView_ = new EbitenSurfaceView(context, attrs);
+    }
+
+    @Override
+    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
+        if (!initialized_) {
+            LayoutParams params = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
+            addView(ebitenSurfaceView_, params);
+            initialized_ = true;
+        }
+
+        int widthInDp = (int)Math.floor(pxToDp(right - left));
+        int heightInDp = (int)Math.floor(pxToDp(bottom - top));
+        Ebitenmobileview.layout(widthInDp, heightInDp, new ViewRectSetter() {
+            @Override
+            public void setViewRect(long xInDp, long yInDp, long widthInDp, long heightInDp) {
+                int widthInPx = (int)Math.ceil(dpToPx(widthInDp));
+                int heightInPx = (int)Math.ceil(dpToPx(heightInDp));
+                int xInPx = (int)Math.ceil(dpToPx(xInDp));
+                int yInPx = (int)Math.ceil(dpToPx(yInDp));
+                ebitenSurfaceView_.layout(xInPx, yInPx, xInPx + widthInPx, yInPx + heightInPx);
+            }
+        });
+    }
+
+    public void onPause() {
+        if (initialized_) {
+            ebitenSurfaceView_.onPause();
+        }
+    }
+
+    public void onResume() {
+        if (initialized_) {
+            ebitenSurfaceView_.onPause();
+        }
+    }
+
+    private EbitenSurfaceView ebitenSurfaceView_;
+    private boolean initialized_ = false;
+}
+`
+
+const surfaceViewJava = `// Code generated by ebitenmobile. DO NOT EDIT.
+
+package {{.JavaPkg}}.{{.PrefixLower}};
+
+import android.content.Context;
+import android.opengl.GLSurfaceView;
+import android.util.Log;
+import android.util.AttributeSet;
+import android.view.MotionEvent;
+
+import javax.microedition.khronos.egl.EGLConfig;
+import javax.microedition.khronos.opengles.GL10;
+
+import {{.JavaPkg}}.ebitenmobileview.Ebitenmobileview;
+
+class EbitenSurfaceView extends GLSurfaceView {
+
+    private class EbitenRenderer implements Renderer {
+
+        private boolean errored_ = false;
+
+        @Override
+        public void onDrawFrame(GL10 gl) {
+            if (errored_) {
+                return;
+            }
+            try {
+                Ebitenmobileview.update();
+            } catch (Exception e) {
+                for (String line : e.toString().split("\\n")) {
+                    Log.e("Go Error", line);
+                }
+                errored_ = true;
+            }
+        }
+
+        @Override
+        public void onSurfaceCreated(GL10 gl, EGLConfig config) {
+        }
+
+        @Override
+        public void onSurfaceChanged(GL10 gl, int width, int height) {
+        }
+    }
+
+    public EbitenSurfaceView(Context context) {
+        super(context);
+        initialize();
+    }
+
+    public EbitenSurfaceView(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        initialize();
+    }
+
+    private void initialize() {
+        setEGLContextClientVersion(2);
+        setEGLConfigChooser(8, 8, 8, 8, 0, 0);
+        setRenderer(new EbitenRenderer());
+    }
+
+    private double getDeviceScale() {
+        if (deviceScale_ == 0.0) {
+            deviceScale_ = getResources().getDisplayMetrics().density;
+        }
+        return deviceScale_;
+    }
+
+    private double pxToDp(double x) {
+        return x / getDeviceScale();
+    }
+
+    @Override
+    public boolean onTouchEvent(MotionEvent e) {
+        for (int i = 0; i < e.getPointerCount(); i++) {
+            int id = e.getPointerId(i);
+            int x = (int)e.getX(i);
+            int y = (int)e.getY(i);
+            Ebitenmobileview.updateTouchesOnAndroid(e.getActionMasked(), id, (int)pxToDp(x), (int)pxToDp(y));
+        }
+        return true;
+    }
+
+    private double deviceScale_ = 0.0;
+}
+`