DiffSliderView.java

/*
 * Copyright (c) 2011, 2012 Roberto Tyley
 *
 * This file is part of 'Agit' - an Android Git client.
 *
 * Agit is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Agit is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see http://www.gnu.org/licenses/ .
 */

package com.madgag.agit.diff;

import static android.content.Context.VIBRATOR_SERVICE;
import static android.graphics.Typeface.BOLD;
import static android.graphics.Typeface.create;
import static android.view.Gravity.CENTER;
import static com.madgag.agit.R.id.DiffPlayerSeekBar;
import static com.madgag.agit.R.id.afterText;
import static com.madgag.agit.R.id.beforeText;
import static com.madgag.agit.R.layout.diff_seekbar_view;
import android.content.Context;
import android.graphics.Typeface;
import android.os.Vibrator;
import android.util.AttributeSet;
import android.util.Log;
import android.view.LayoutInflater;
import android.widget.LinearLayout;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;
import android.widget.TextView;

public class DiffSliderView extends LinearLayout {

    private String TAG = "DSV";

    public static interface OnStateUpdateListener {
        void onStateChanged(DiffSliderView diffSliderView, float state);
    }

    private OnStateUpdateListener stateUpdateListener;
    private final TextView beforeTextView, afterTextView;
    private final Typeface defaultTypeface, boldTypeFace;

    public DiffSliderView(Context context, AttributeSet attrs) {
        super(context, attrs);
        setOrientation(HORIZONTAL);
        setGravity(CENTER);
        LayoutInflater.from(context).inflate(diff_seekbar_view, this);

        beforeTextView = (TextView) findViewById(beforeText);
        afterTextView = (TextView) findViewById(afterText);
        defaultTypeface = beforeTextView.getTypeface();
        boldTypeFace = create(defaultTypeface, BOLD);

        SeekBar seekBar = (SeekBar) findViewById(DiffPlayerSeekBar);
        seekBar.setProgress(seekBar.getMax() / 2);
        // After initial progress is set, initiate the vibration feedback
        Vibrator vibrator = (Vibrator) context.getSystemService(VIBRATOR_SERVICE);
        seekBar.setOnSeekBarChangeListener(new DiffSeekBarChangeListener(vibrator));
    }

    public void setStateUpdateListener(OnStateUpdateListener stateUpdateListener) {
        this.stateUpdateListener = stateUpdateListener;
    }


    class DiffSeekBarChangeListener implements OnSeekBarChangeListener {
        private final Vibrator vibrator;

        public DiffSeekBarChangeListener(Vibrator vibrator) {
            this.vibrator = vibrator;
        }

        public void onStopTrackingTouch(SeekBar seekBar) {
            // TODO - should we animate this movement?
            int sector = (int) (unitProgress(seekBar) * 3); // 0 ,1 ,2
            int progress = (sector * seekBar.getMax()) / 2;
            seekBar.setProgress(progress);
        }

        public void onStartTrackingTouch(SeekBar seekBar) {
        }

        public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
            boolean before = progress == 0, after = seekBar.getMax() == progress, middle = seekBar.getMax() / 2 ==
                    progress;
            if (before || after || middle) {
                vibrator.vibrate(17);
            }
            // sadly makes the damn seekbar wiggle
//            beforeTextView.setTypeface(before?boldTypeFace:defaultTypeface);
//            afterTextView.setTypeface(after?boldTypeFace:defaultTypeface);
            float unitProgress = unitProgress(seekBar);

            notifyTheOthers(unitProgress);

        }


        private float unitProgress(SeekBar seekBar) {
            return ((float) seekBar.getProgress()) / seekBar.getMax();
        }
    }

    private void notifyTheOthers(float unitProgress) {
        Log.d(TAG, "notifyTheOthers stateUpdateListener=" + stateUpdateListener);
        if (stateUpdateListener != null) {
            stateUpdateListener.onStateChanged(this, unitProgress);
        }
    }
}