CustomTransitionSample.java

/*
 * Copyright (C) 2016 Andrey Kulikov (andkulikov@gmail.com)
 *
 * 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.andkulikov.transitionseverywhere;

import android.animation.Animator;
import android.animation.ObjectAnimator;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.util.Property;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ProgressBar;

import com.transitionseverywhere.Transition;
import com.transitionseverywhere.TransitionManager;
import com.transitionseverywhere.TransitionValues;
import com.transitionseverywhere.utils.IntProperty;

/**
 * Created by Andrey Kulikov on 17/04/16.
 */
public class CustomTransitionSample extends Fragment {

    private ViewGroup mTransitionsContainer;
    private ProgressBar mProgressBar;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_custom, container, false);

        mTransitionsContainer = (ViewGroup) view.findViewById(R.id.transitions_container);
        mProgressBar = (ProgressBar) view.findViewById(R.id.progress_bar);

        view.findViewById(R.id.button1).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                setProgress(mProgressBar.getProgress() - 20);
            }
        });
        view.findViewById(R.id.button2).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                setProgress(mProgressBar.getProgress() + 30);
            }
        });

        return view;
    }

    private void setProgress(int value) {
        TransitionManager.beginDelayedTransition(mTransitionsContainer, new ProgressTransition());
        value = Math.max(0, Math.min(100, value));
        mProgressBar.setProgress(value);
    }

    private static class ProgressTransition extends Transition {

        /**
         * Property is like a helper that contain setter and getter in one place
         */
        private static final Property<ProgressBar, Integer> PROGRESS_PROPERTY = new IntProperty<ProgressBar>() {

            @Override
            public void setValue(ProgressBar progressBar, int value) {
                progressBar.setProgress(value);
            }

            @Override
            public Integer get(ProgressBar progressBar) {
                return progressBar.getProgress();
            }
        }.optimize();

        /**
         * Internal name of property. Like a bundles for intent
         */
        private static final String PROPNAME_PROGRESS = "ProgressTransition:progress";

        @Override
        public void captureStartValues(TransitionValues transitionValues) {
            captureValues(transitionValues);
        }

        @Override
        public void captureEndValues(TransitionValues transitionValues) {
            captureValues(transitionValues);
        }

        private void captureValues(TransitionValues transitionValues) {
            if (transitionValues.view instanceof ProgressBar) {
                // save current progress in the values map
                ProgressBar progressBar = ((ProgressBar) transitionValues.view);
                transitionValues.values.put(PROPNAME_PROGRESS, progressBar.getProgress());
            }
        }

        @Override
        public Animator createAnimator(ViewGroup sceneRoot, TransitionValues startValues, TransitionValues endValues) {
            if (startValues != null && endValues != null && endValues.view instanceof ProgressBar) {
                ProgressBar progressBar = (ProgressBar) endValues.view;
                int start = (Integer) startValues.values.get(PROPNAME_PROGRESS);
                int end = (Integer) endValues.values.get(PROPNAME_PROGRESS);
                if (start != end) {
                    // first of all we need to return the start value, because right now
                    // the view is have the end value
                    progressBar.setProgress(start);
                    // create animator with our progressBar, property and end value
                    return ObjectAnimator.ofInt(progressBar, PROGRESS_PROPERTY, end);
                }
            }
            return null;
        }
    }

}