ANDROID: Add a LED widget and use it to indicate IO activity in SAF

This will notify the user of IOs by blinking the LED. This indicates
that ScummVM is busy and not hung.

backends/platform/android/org/scummvm/scummvm/LedView.java

@@ -0,0 +1,168 @@
+package org.scummvm.scummvm;
+
+import android.content.Context;
+import android.content.res.TypedArray;
+import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.util.AttributeSet;
+import android.view.View;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.annotation.RequiresApi;
+
+public class LedView extends View {
+	public static final int DEFAULT_LED_COLOR = 0xffff0000;
+	private static final int BLINK_TIME = 30; // ms
+
+	private boolean _state;
+	private Runnable _blink;
+	private Paint _painter;
+	private int _radius;
+	private int _centerX;
+	private int _centerY;
+
+	public LedView(Context context) {
+		this(context, true, DEFAULT_LED_COLOR);
+	}
+
+	public LedView(Context context, boolean state) {
+			this(context, state, DEFAULT_LED_COLOR);
+	}
+
+	public LedView(Context context, boolean state, int color) {
+		super(context);
+		_state = state;
+		init(color);
+	}
+
+	public LedView(Context context, @Nullable AttributeSet attrs) {
+		this(context, attrs, 0);
+	}
+
+	public LedView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
+		super(context, attrs, defStyleAttr);
+		init(context, attrs, defStyleAttr, 0);
+	}
+
+	@RequiresApi(android.os.Build.VERSION_CODES.LOLLIPOP)
+	public LedView(
+		Context context, @Nullable AttributeSet attrs, int defStyleAttr, int defStyleRes) {
+		super(context, attrs, defStyleAttr, defStyleRes);
+		init(context, attrs, defStyleAttr, defStyleRes);
+	}
+
+	private void init(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
+		TypedArray a = context.getTheme().obtainStyledAttributes(
+			attrs,
+			R.styleable.LedView,
+			defStyleAttr, defStyleRes);
+
+		try {
+			_state = a.getBoolean(R.styleable.LedView_state, true);
+			int color = a.getColor(R.styleable.LedView_color, DEFAULT_LED_COLOR);
+			init(color);
+		} finally {
+			a.recycle();
+		}
+	}
+
+	private void init(int color) {
+		_painter = new Paint();
+		_painter.setStyle(Paint.Style.FILL);
+		if (isInEditMode()) {
+			_painter.setStrokeWidth(2);
+			_painter.setStyle(_state ? Paint.Style.FILL : Paint.Style.STROKE);
+		}
+		_painter.setColor(color);
+		_painter.setAntiAlias(true);
+	}
+
+	@Override
+	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+		int minw = getPaddingLeft() + getPaddingRight() + getSuggestedMinimumWidth();
+		int w = resolveSizeAndState(minw, widthMeasureSpec, 0);
+
+		int minh = MeasureSpec.getSize(w) - getPaddingLeft() - getPaddingRight() +
+			getPaddingBottom() + getPaddingTop();
+		int h = resolveSizeAndState(minh, heightMeasureSpec, 0);
+
+		setMeasuredDimension(w, h);
+	}
+
+	@Override
+	protected void onSizeChanged(int w, int h, int oldw, int oldh) {
+		super.onSizeChanged(w, h, oldw, oldh);
+
+		int xpad = (getPaddingLeft() + getPaddingRight());
+		int ypad = (getPaddingTop() + getPaddingBottom());
+
+		int ww = w - xpad;
+		int hh = h - ypad;
+
+		_radius = Math.min(ww, hh) / 2 - 2;
+		_centerX = w / 2;
+		_centerY = h / 2;
+	}
+
+	@Override
+	protected void onDraw(@NonNull Canvas canvas) {
+		super.onDraw(canvas);
+
+		if (!_state && !isInEditMode()) {
+			return;
+		}
+
+		canvas.drawCircle(_centerX, _centerY, _radius, _painter);
+	}
+
+	public void on() {
+		setState(true);
+	}
+
+	public void off() {
+		setState(false);
+	}
+
+	public void setState(boolean state) {
+		if (_blink != null) {
+			removeCallbacks(_blink);
+			_blink = null;
+		}
+
+		if (_state == state) {
+			return;
+		}
+		_state = state;
+		invalidate();
+	}
+
+	public void blinkOnce() {
+		if (_blink != null) {
+			return;
+		}
+
+		boolean oldState = _state;
+		_state = !oldState;
+		invalidate();
+
+		_blink = new Runnable() {
+			private boolean _ran;
+
+			@Override
+			public void run() {
+				if (_ran) {
+					_blink = null;
+					return;
+				}
+
+				_ran = true;
+				_state = oldState;
+				invalidate();
+
+				postDelayed(this, BLINK_TIME);
+			}
+		};
+		postDelayed(_blink, BLINK_TIME);
+	}
+}

backends/platform/android/org/scummvm/scummvm/ScummVMActivity.java

@@ -117,6 +117,7 @@ public class ScummVMActivity extends Activity implements OnKeyboardVisibilityLis
 	private GridLayout _buttonLayout = null;
 	private ImageView _toggleTouchModeKeyboardBtnIcon = null;
 	private ImageView _openMenuBtnIcon = null;
+	private LedView _ioLed = null;
 	private int _layoutOrientation;
 
 	public View _screenKeyboard = null;
@@ -531,6 +532,9 @@ private void layoutButtonLayout(int orientation, boolean force) {
 			params = (GridLayout.LayoutParams)_toggleTouchModeKeyboardBtnIcon.getLayoutParams();
 			params.rowSpec = GridLayout.spec(1);
 			params.columnSpec = GridLayout.spec(1);
+			params = (GridLayout.LayoutParams)_ioLed.getLayoutParams();
+			params.rowSpec = GridLayout.spec(0, 2, GridLayout.TOP);
+			params.columnSpec = GridLayout.spec(0, GridLayout.RIGHT);
 		} else {
 			GridLayout.LayoutParams params;
 			params = (GridLayout.LayoutParams)_openMenuBtnIcon.getLayoutParams();
@@ -539,6 +543,9 @@ private void layoutButtonLayout(int orientation, boolean force) {
 			params = (GridLayout.LayoutParams)_toggleTouchModeKeyboardBtnIcon.getLayoutParams();
 			params.rowSpec = GridLayout.spec(0);
 			params.columnSpec = GridLayout.spec(0);
+			params = (GridLayout.LayoutParams)_ioLed.getLayoutParams();
+			params.rowSpec = GridLayout.spec(1, GridLayout.TOP);
+			params.columnSpec = GridLayout.spec(0, 2, GridLayout.RIGHT);
 		}
 		_buttonLayout.requestLayout();
 	}
@@ -932,6 +939,7 @@ public void onCreate(Bundle savedInstanceState) {
 		_buttonLayout = findViewById(R.id.button_layout);
 		_openMenuBtnIcon = findViewById(R.id.open_menu_button);
 		_toggleTouchModeKeyboardBtnIcon = findViewById(R.id.toggle_touch_button);
+		_ioLed = findViewById(R.id.io_led);
 
 		// Hide by default all buttons, they will be shown when native code will start
 		showToggleOnScreenBtnIcons(0);
@@ -1043,6 +1051,18 @@ public void handle(int exitResult) {
 			_main_surface.setOnHoverListener(_mouseHelper);
 		}
 
+		SAFFSTree.setIOBusyListener(new SAFFSTree.IOBusyListener() {
+			@Override
+			public void onIOBusy(float ratio) {
+				runOnUiThread(new Runnable() {
+					@Override
+					public void run() {
+						_ioLed.blinkOnce();
+					}
+				});
+			}
+		});
+
 		_scummvm_thread = new Thread(_scummvm, "ScummVM");
 		_scummvm_thread.start();
 	}
@@ -1159,6 +1179,8 @@ public void onDestroy() {
 
 		super.onDestroy();
 
+		SAFFSTree.setIOBusyListener(null);
+
 		if (isScreenKeyboardShown()) {
 			hideScreenKeyboard();
 		}

dists/android/res/layout/scummvm_activity.xml

@@ -43,6 +43,16 @@
 			android:src="@drawable/ic_action_menu"
 			android:visibility="gone"
 			tools:visibility="visible" />
+
+		<org.scummvm.scummvm.LedView
+			android:id="@+id/io_led"
+			android:layout_width="5dp"
+			android:layout_height="wrap_content"
+			android:layout_row="1"
+			android:layout_column="0"
+			android:layout_columnSpan="2"
+			android:layout_gravity="right|top"
+			app:state="false" />
 	</GridLayout>
 
 </FrameLayout>

dists/android/res/values/attrs.xml

@@ -0,0 +1,6 @@
+<resources>
+   <declare-styleable name="LedView">
+	   <attr name="color" format="reference|color" />
+	   <attr name="state" format="boolean" />
+   </declare-styleable>
+</resources>