Java tutorial
/* * Copyright 2013 Google 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.example.flashcards; import java.util.List; import android.app.Activity; import android.os.Bundle; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentActivity; import android.support.v4.app.FragmentManager; import android.support.v4.app.FragmentStatePagerAdapter; import android.support.v4.view.ViewPager; import android.util.TypedValue; import android.view.View; import android.view.ViewGroup; import android.widget.Button; import com.example.flashcards.entity.Topic; import com.example.flashcards.entity.Word; import com.example.flashcards.mvc.Controller; import com.example.flashcards.wizard.NewWordWizardModel; import com.example.flashcards.wizardpager.wizard.model.AbstractWizardModel; import com.example.flashcards.wizardpager.wizard.model.HandInputWordPage; import com.example.flashcards.wizardpager.wizard.model.ModelCallbacks; import com.example.flashcards.wizardpager.wizard.model.Page; import com.example.flashcards.wizardpager.wizard.model.SingleTopicChoicePage; import com.example.flashcards.wizardpager.wizard.ui.PageFragmentCallbacks; import com.example.flashcards.wizardpager.wizard.ui.ReviewFragment; import com.example.flashcards.wizardpager.wizard.ui.StepPagerStrip; public class WizardActivity extends FragmentActivity implements PageFragmentCallbacks, ReviewFragment.Callbacks, ModelCallbacks { private ViewPager mPager; private MyPagerAdapter mPagerAdapter; private boolean mEditingAfterReview; private AbstractWizardModel mWizardModel = new NewWordWizardModel(this); private boolean mConsumePageSelectedEvent; private Button mNextButton; private Button mPrevButton; private List<Page> mCurrentPageSequence; private StepPagerStrip mStepPagerStrip; public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_wizard); if (savedInstanceState != null) { mWizardModel.load(savedInstanceState.getBundle("model")); } mWizardModel.registerListener(this); mPagerAdapter = new MyPagerAdapter(getSupportFragmentManager()); mPager = (ViewPager) findViewById(R.id.pager); mPager.setAdapter(mPagerAdapter); mStepPagerStrip = (StepPagerStrip) findViewById(R.id.strip); mStepPagerStrip.setOnPageSelectedListener(new StepPagerStrip.OnPageSelectedListener() { @Override public void onPageStripSelected(int position) { position = Math.min(mPagerAdapter.getCount() - 1, position); if (mPager.getCurrentItem() != position) { mPager.setCurrentItem(position); } } }); mNextButton = (Button) findViewById(R.id.next_button); mPrevButton = (Button) findViewById(R.id.prev_button); mPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() { @Override public void onPageSelected(int position) { mStepPagerStrip.setCurrentPage(position); if (mConsumePageSelectedEvent) { mConsumePageSelectedEvent = false; return; } mEditingAfterReview = false; updateBottomBar(); } }); final Activity activity = this; mNextButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { if (mPager.getCurrentItem() == mCurrentPageSequence.size()) { callNewWord(); try { activity.finish(); } catch (Throwable e) { // TODO Auto-generated catch block e.printStackTrace(); } } else { if (mEditingAfterReview) { mPager.setCurrentItem(mPagerAdapter.getCount() - 1); } else { mPager.setCurrentItem(mPager.getCurrentItem() + 1); } } } }); mPrevButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { mPager.setCurrentItem(mPager.getCurrentItem() - 1); } }); onPageTreeChanged(); updateBottomBar(); } private void callNewWord() { String first = getJointBundle().getString(HandInputWordPage.FIRST); String second = getJointBundle().getString(HandInputWordPage.SECOND); Topic topic = (Topic) getJointBundle().getSerializable(SingleTopicChoicePage.TOPIC); Controller.getInstanceOf().addNewWord(new Word(first, second, null, topic)); } private Bundle getJointBundle() { Bundle result = new Bundle(); for (Page page : mCurrentPageSequence) { result.putAll(page.getData()); } return result; } @Override public void onPageTreeChanged() { mCurrentPageSequence = mWizardModel.getCurrentPageSequence(); recalculateCutOffPage(); mStepPagerStrip.setPageCount(mCurrentPageSequence.size() + 1); // + 1 = review step mPagerAdapter.notifyDataSetChanged(); updateBottomBar(); } private void updateBottomBar() { int position = mPager.getCurrentItem(); if (position == mCurrentPageSequence.size()) { mNextButton.setText(R.string.finish); mNextButton.setBackgroundResource(R.drawable.finish_background); mNextButton.setTextAppearance(this, R.style.TextAppearanceFinish); } else { mNextButton.setText(mEditingAfterReview ? R.string.review : R.string.next); mNextButton.setBackgroundResource(R.drawable.selectable_item_background); TypedValue v = new TypedValue(); getTheme().resolveAttribute(android.R.attr.textAppearanceMedium, v, true); mNextButton.setTextAppearance(this, v.resourceId); mNextButton.setEnabled(position != mPagerAdapter.getCutOffPage()); } mPrevButton.setVisibility(position <= 0 ? View.INVISIBLE : View.VISIBLE); } @Override protected void onDestroy() { super.onDestroy(); mWizardModel.unregisterListener(this); } @Override protected void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); outState.putBundle("model", mWizardModel.save()); } @Override public AbstractWizardModel onGetModel() { return mWizardModel; } @Override public void onEditScreenAfterReview(String key) { for (int i = mCurrentPageSequence.size() - 1; i >= 0; i--) { if (mCurrentPageSequence.get(i).getKey().equals(key)) { mConsumePageSelectedEvent = true; mEditingAfterReview = true; mPager.setCurrentItem(i); updateBottomBar(); break; } } } @Override public void onPageDataChanged(Page page) { if (page.isRequired()) { if (recalculateCutOffPage()) { mPagerAdapter.notifyDataSetChanged(); updateBottomBar(); } } } @Override public Page onGetPage(String key) { return mWizardModel.findByKey(key); } private boolean recalculateCutOffPage() { // Cut off the pager adapter at first required page that isn't completed int cutOffPage = mCurrentPageSequence.size() + 1; for (int i = 0; i < mCurrentPageSequence.size(); i++) { Page page = mCurrentPageSequence.get(i); if (page.isRequired() && !page.isCompleted()) { cutOffPage = i; break; } } if (mPagerAdapter.getCutOffPage() != cutOffPage) { mPagerAdapter.setCutOffPage(cutOffPage); return true; } return false; } public class MyPagerAdapter extends FragmentStatePagerAdapter { private int mCutOffPage; private Fragment mPrimaryItem; public MyPagerAdapter(FragmentManager fm) { super(fm); } @Override public Fragment getItem(int i) { if (i >= mCurrentPageSequence.size()) { return new ReviewFragment(); } return mCurrentPageSequence.get(i).createFragment(); } @Override public int getItemPosition(Object object) { // TODO: be smarter about this if (object == mPrimaryItem) { // Re-use the current fragment (its position never changes) return POSITION_UNCHANGED; } return POSITION_NONE; } @Override public void setPrimaryItem(ViewGroup container, int position, Object object) { super.setPrimaryItem(container, position, object); mPrimaryItem = (Fragment) object; } @Override public int getCount() { if (mCurrentPageSequence == null) { return 0; } return Math.min(mCutOffPage + 1, mCurrentPageSequence.size() + 1); } public void setCutOffPage(int cutOffPage) { if (cutOffPage < 0) { cutOffPage = Integer.MAX_VALUE; } mCutOffPage = cutOffPage; } public int getCutOffPage() { return mCutOffPage; } } }