TweetFragment.java

/* $Id: $
   Copyright 2012, G. Blake Meike

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
 */
package com.twitter.university.android.yamba;

import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.annotation.TargetApi;
import android.app.Fragment;
import android.content.res.Resources;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewAnimationUtils;
import android.view.ViewGroup;
import android.widget.EditText;
import android.widget.TextView;

import com.twitter.university.android.yamba.svc.YambaService;


public class TweetFragment extends Fragment {
    private static final int BUTTON_HIDE = -1;
    private static final int BUTTON_HIDE_DELAY = 600;

    private class AnimationHandler extends Handler {
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case BUTTON_HIDE: hideButton(); break;
            }
        }
    }

    private int okColor;
    private int warnColor;
    private int errColor;

    private int tweetMax;
    private int warnMax;
    private int errMax;

    private EditText tweetView;
    private TextView countView;
    private View submitButton;

    private int buttonDiameter;

    private boolean buttonVisible;

    private Handler handler;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        Resources rez = getResources();

        okColor = rez.getColor(R.color.tweet_len_ok);
        warnColor = rez.getColor(R.color.tweet_len_warn);
        errColor = rez.getColor(R.color.tweet_len_err);

        tweetMax = rez.getInteger(R.integer.tweet_max);
        warnMax = rez.getInteger(R.integer.warn_max);
        errMax = rez.getInteger(R.integer.err_max);

        buttonDiameter = rez.getDimensionPixelSize(R.dimen.button_diameter);

        handler = new AnimationHandler();
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup root, Bundle state) {
       View v = inflater.inflate(R.layout.fragment_tweet, root, false);

        View button = v.findViewById(R.id.tweet_submit);
        button.setOnClickListener(
            new View.OnClickListener() {
                @Override public void onClick(View v) { post(); }
            } );
        button.addOnAttachStateChangeListener(
            new View.OnAttachStateChangeListener() {
                @Override public void onViewDetachedFromWindow(View v) { submitButton = null; }
                @Override public void onViewAttachedToWindow(View v) {
                    submitButton = v;
                    updateCount();
                }
        } );

        countView = (TextView) v.findViewById(R.id.tweet_count);
        tweetView = (EditText) v.findViewById(R.id.tweet_tweet);
        tweetView.addTextChangedListener(
            new TextWatcher() {
                @Override public void afterTextChanged(Editable str) { updateCount(); }
                @Override public void beforeTextChanged(CharSequence str, int s, int c, int a) { }
                @Override public void onTextChanged(CharSequence str, int s, int c, int a) { }
            }
        );

        return v;
    }

    void updateCount() {
        int n = tweetView.getText().length();

        boolean visible = canTweet(n);
        if (YambaApplication.USING_MATERIAL) { animateButton(submitButton, visible); }
        else {
            if (null != submitButton) { submitButton.setEnabled(visible); }
        }

        n = tweetMax - n;

        int color;
        if (n > warnMax) { color = okColor; }
        else if (n > errMax) { color = warnColor; }
        else  { color = errColor; }

        countView.setText(String.valueOf(n));
        countView.setTextColor(color);
    }

    void post() {
        String tweet = tweetView.getText().toString();
        if (!canTweet(tweet.length())) { return; }

        tweetView.setText("");

        YambaService.postTweet(getActivity(), tweet);
    }

    private boolean canTweet(int n) {
        return (errMax < n) && (tweetMax > n);
    }

    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    private void animateButton(View button, boolean visible) {
        if ((submitButton == null) || buttonVisible == visible) { return; }

        if (!visible) {
            handler.sendMessageDelayed(handler.obtainMessage(BUTTON_HIDE), BUTTON_HIDE_DELAY);
            return;
        }

        int ctr = buttonDiameter / 2;
        submitButton.setVisibility(View.VISIBLE);
        ViewAnimationUtils.createCircularReveal(submitButton, ctr, ctr, 0, buttonDiameter).start();
        buttonVisible = true;
    }

    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    void hideButton() {
        if ((null == submitButton) || !buttonVisible) { return; }

        int ctr = buttonDiameter / 2;

        Animator anim = ViewAnimationUtils.createCircularReveal(submitButton, ctr, ctr, buttonDiameter, 0);
        anim.addListener(new AnimatorListenerAdapter() {
            @Override
            public void onAnimationEnd(Animator animation) {
                super.onAnimationEnd(animation);
                if (null != submitButton) { submitButton.setVisibility(View.INVISIBLE); }
                buttonVisible = false;
            }
        });

        anim.start();
    }
}