Java tutorial
/* * Copyright 2015 Udacity, Inc * * 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.udacity.interpolationdemo; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.support.v7.internal.widget.AdapterViewCompat; import android.util.DisplayMetrics; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.view.animation.Interpolator; import android.widget.AdapterView; import android.widget.Spinner; import android.widget.TextView; import android.widget.Toast; import butterknife.Bind; import butterknife.ButterKnife; import butterknife.OnItemSelected; import butterknife.OnItemSelected.Callback.*; public class MainActivity extends AppCompatActivity { @Bind(R.id.interpolator_spinner) Spinner interpolatorSpinner; @Bind(R.id.duration_spinner) Spinner duratorSpinner; @Bind(R.id.textView) TextView textView; private static final String PACKAGE = "android.view.animation."; private static final String PACKAGE_V4 = "android.support.v4.view.animation."; private int duration; private Interpolator interpolator; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); ButterKnife.bind(this); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.menu_main, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { // Handle action bar item clicks here. The action bar will // automatically handle clicks on the Home/Up button, so long // as you specify a parent activity in AndroidManifest.xml. int id = item.getItemId(); //noinspection SimplifiableIfStatement if (id == R.id.action_settings) { return true; } return super.onOptionsItemSelected(item); } @OnItemSelected({ R.id.duration_spinner }) void durationSelected(Spinner spinner, int position) { String durationString = (String) spinner.getAdapter().getItem(position); switch (durationString) { case "100ms": duration = 100; case "900ms": duration = 900; break; case "1500ms": duration = 1500; break; case "3000ms": duration = 3000; break; default: duration = 300; break; } // Kick off transition int item = interpolatorSpinner.getSelectedItemPosition(); onItemSelected(interpolatorSpinner, position); } String findFullInterpolatorPath(String className) { if (className.equals("FastOutLinearInInterpolator") || className.equals("FastOutSlowInInterpolator") || className.equals("LinearOutSlowInInterpolator")) return PACKAGE_V4 + className; else if (className.startsWith("-")) return null; else return PACKAGE + className; } @OnItemSelected({ R.id.interpolator_spinner }) void onItemSelected(Spinner spinner, int position) { String interpolatorName = (String) spinner.getAdapter().getItem(position); DisplayMetrics metrics = new DisplayMetrics(); getWindowManager().getDefaultDisplay().getMetrics(metrics); textView.setTranslationY(metrics.heightPixels); try { String path = findFullInterpolatorPath(interpolatorName); if (path == null) return; interpolator = (Interpolator) Class.forName(path).newInstance(); textView.animate().setInterpolator(interpolator).setDuration(duration).setStartDelay(500) .translationYBy(-metrics.heightPixels).start(); } catch (Exception ex) { ex.printStackTrace(); } } @OnItemSelected(value = R.id.interpolator_spinner, callback = OnItemSelected.Callback.NOTHING_SELECTED) void onNothingSelected() { } }