Java tutorial
/* * This is the source code of Telegram for Android v. 1.3.2. * It is licensed under GNU GPL v. 2 or later. * You should have received a copy of the license in this archive (see LICENSE). * * Copyright Nikolai Kudashov, 2013. */ package com.odt.kandani.View; import android.app.Activity; import android.content.Intent; import android.content.pm.ActivityInfo; import android.database.DataSetObserver; import android.os.Bundle; import android.os.Parcelable; import android.support.v4.view.PagerAdapter; import android.support.v4.view.ViewPager; import android.text.Html; import android.view.View; import android.view.ViewGroup; import android.view.Window; import android.view.animation.Animation; import android.view.animation.AnimationUtils; import android.widget.ImageView; import android.widget.TextView; import com.odt.kandani.R; public class IntroActivity extends Activity { private ViewPager viewPager; private ImageView topImage1; private ImageView topImage2; private ViewGroup bottomPages; private int lastPage = 0; private boolean justCreated = false; private boolean startPressed = false; private int[] icons; private int[] titles; private int[] messages; @Override protected void onCreate(Bundle savedInstanceState) { setTheme(R.style.Theme_TMessages); super.onCreate(savedInstanceState); requestWindowFeature(Window.FEATURE_NO_TITLE); setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT); setContentView(R.layout.activity_layout); icons = new int[] { R.drawable.intro1, R.drawable.intro2, R.drawable.intro3, R.drawable.intro4 }; titles = new int[] { R.string.Page1Title, R.string.Page2Title, R.string.Page3Title, R.string.Page4Title }; messages = new int[] { R.string.Page1Message, R.string.Page2Message, R.string.Page3Message, R.string.Page4Message }; viewPager = (ViewPager) findViewById(R.id.intro_view_pager); TextView startMessagingButton = (TextView) findViewById(R.id.start_messaging_button); topImage1 = (ImageView) findViewById(R.id.icon_image1); topImage2 = (ImageView) findViewById(R.id.icon_image2); bottomPages = (ViewGroup) findViewById(R.id.bottom_pages); topImage2.setVisibility(View.GONE); viewPager.setAdapter(new IntroAdapter()); viewPager.setPageMargin(0); viewPager.setOffscreenPageLimit(1); viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() { @Override public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { } @Override public void onPageSelected(int i) { } @Override public void onPageScrollStateChanged(int i) { if (i == ViewPager.SCROLL_STATE_IDLE || i == ViewPager.SCROLL_STATE_SETTLING) { if (lastPage != viewPager.getCurrentItem()) { lastPage = viewPager.getCurrentItem(); final ImageView fadeoutImage; final ImageView fadeinImage; if (topImage1.getVisibility() == View.VISIBLE) { fadeoutImage = topImage1; fadeinImage = topImage2; } else { fadeoutImage = topImage2; fadeinImage = topImage1; } fadeinImage.bringToFront(); fadeinImage.setImageResource(icons[lastPage]); fadeinImage.clearAnimation(); fadeoutImage.clearAnimation(); Animation outAnimation = AnimationUtils.loadAnimation(IntroActivity.this, R.anim.icon_anim_fade_out); outAnimation.setAnimationListener(new Animation.AnimationListener() { @Override public void onAnimationStart(Animation animation) { } @Override public void onAnimationEnd(Animation animation) { fadeoutImage.setVisibility(View.GONE); } @Override public void onAnimationRepeat(Animation animation) { } }); Animation inAnimation = AnimationUtils.loadAnimation(IntroActivity.this, R.anim.icon_anim_fade_in); inAnimation.setAnimationListener(new Animation.AnimationListener() { @Override public void onAnimationStart(Animation animation) { fadeinImage.setVisibility(View.VISIBLE); } @Override public void onAnimationEnd(Animation animation) { } @Override public void onAnimationRepeat(Animation animation) { } }); fadeoutImage.startAnimation(outAnimation); fadeinImage.startAnimation(inAnimation); } } } }); startMessagingButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Intent intent = new Intent(IntroActivity.this, MainActivity.class); IntroActivity.this.startActivity(intent); overridePendingTransition(R.anim.pull_in_right, R.anim.push_out_left); IntroActivity.this.finish(); } }); justCreated = true; } @Override protected void onResume() { super.onResume(); if (justCreated) { viewPager.setCurrentItem(0); lastPage = 0; justCreated = false; } } private class IntroAdapter extends PagerAdapter { @Override public int getCount() { return 4; } @Override public Object instantiateItem(ViewGroup container, int position) { View view = View.inflate(container.getContext(), R.layout.intro_view_layout, null); TextView headerTextView = (TextView) view.findViewById(R.id.header_text); TextView messageTextView = (TextView) view.findViewById(R.id.message_text); container.addView(view, 0); headerTextView.setText(getString(titles[position])); messageTextView.setText(Html.fromHtml(getString(messages[position]))); return view; } @Override public void destroyItem(ViewGroup container, int position, Object object) { container.removeView((View) object); } @Override public void setPrimaryItem(ViewGroup container, int position, Object object) { super.setPrimaryItem(container, position, object); int count = bottomPages.getChildCount(); for (int a = 0; a < count; a++) { View child = bottomPages.getChildAt(a); if (a == position) { child.setBackgroundColor(0xff2ca5e0); } else { child.setBackgroundColor(0xffbbbbbb); } } } @Override public boolean isViewFromObject(View view, Object object) { return view.equals(object); } @Override public void finishUpdate(View arg0) { } @Override public void restoreState(Parcelable arg0, ClassLoader arg1) { } @Override public Parcelable saveState() { return null; } @Override public void startUpdate(View arg0) { } @Override public void unregisterDataSetObserver(DataSetObserver observer) { if (observer != null) { super.unregisterDataSetObserver(observer); } } } }