WidgetReceiver.java

package org.solovyev.android.calculator;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Vibrator;
import android.support.annotation.NonNull;
import android.text.TextUtils;

import org.solovyev.android.calculator.buttons.CppButton;
import org.solovyev.android.calculator.history.History;

import javax.annotation.Nonnull;
import javax.inject.Inject;

import static org.solovyev.android.calculator.App.cast;

public final class WidgetReceiver extends BroadcastReceiver {

    public static final String ACTION_BUTTON_ID_EXTRA = "buttonId";
    public static final String ACTION_BUTTON_PRESSED = "org.solovyev.android.calculator.BUTTON_PRESSED";

    @Inject
    Keyboard keyboard;
    @Inject
    History history;

    @Nonnull
    public static Intent newButtonClickedIntent(@Nonnull Context context, @Nonnull CppButton button) {
        final Intent intent = new Intent(context, WidgetReceiver.class);
        intent.setAction(ACTION_BUTTON_PRESSED);
        intent.putExtra(ACTION_BUTTON_ID_EXTRA, button.id);
        return intent;
    }

    @Override
    public void onReceive(Context context, Intent intent) {
        final String action = intent.getAction();
        if (!TextUtils.equals(action, ACTION_BUTTON_PRESSED)) {
            return;
        }

        cast(context).getComponent().inject(this);

        final int buttonId = intent.getIntExtra(ACTION_BUTTON_ID_EXTRA, 0);
        final CppButton button = CppButton.getById(buttonId);
        if (button == null) {
            return;
        }

        if (history.isLoaded()) {
            if (!keyboard.buttonPressed(button.action)) {
                // prevent vibrate
                return;
            }
        } else {
            // if app has been killed we need first to restore the state and only after doing this
            // to apply actions. Otherwise, we will apply actions on the empty editor
            history.runWhenLoaded(new MyRunnable(keyboard, button.action));
        }

        vibrate(context);
    }

    private void vibrate(@NonNull Context context) {
        if (!keyboard.isVibrateOnKeypress()) {
            return;
        }
        final Vibrator vibrator = (Vibrator) context.getSystemService(Context.VIBRATOR_SERVICE);
        if (vibrator == null) {
            return;
        }
        vibrator.vibrate(10);
    }

    private static class MyRunnable implements Runnable {
        @NonNull
        private final Keyboard keyboard;
        @NonNull
        private final String action;

        public MyRunnable(@NonNull Keyboard keyboard, @NonNull String action) {
            this.keyboard = keyboard;
            this.action = action;
        }

        @Override
        public void run() {
            keyboard.buttonPressed(action);
        }
    }
}