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package moe.yuuta.flow;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.constraintlayout.widget.ConstraintLayout;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentStatePagerAdapter;
import androidx.viewpager.widget.ViewPager;
import java.util.ArrayList;
import java.util.List;
/**
* The Host fragment. It is marked as final because it was set to remain instance.
*/
public final class FlowFragment extends Fragment implements IFlowFragment, View.OnClickListener {
private static final String TAG = "FlowFragment";
private List<PageFragment> mPages = new ArrayList<>(0);
// true: after the view settles, update the UI immediately.
private volatile boolean mUIUpdateScheduled;
private static final String ARG_CURRENT = FlowFragment.class.getName() + ".ARG_CURRENT";
private static final String ARG_UI_UPDATE_SCHEDULED = FlowFragment.class.getName() + ".ARG_UI_UPDATE_SCHEDULED";
private Header mHeader;
private ViewPager mPager;
private NavigationBar mNav;
/**
* Should only be called once.
*/
public void setPages(@NonNull List<PageFragment> pages) {
if (mPages != null && mPages.size() > 0) {
throw new IllegalStateException("This method should only be called once. Current size: " + mPages.size());
}
mPages = pages;
// Because this method can be called before setting up the layout, so we need to schedule it until the layout is set up.
notifyCurrentFlowInfoUpdated();
}
/**
* Update the WHOLE UI.
*/
private void updateUI() {
final int currentIndex = mPager.getCurrentItem();
final PageFragment currentFragment = mPages.get(currentIndex);
if (currentFragment.mInfo == null) {
throw new NullPointerException("Info is null");
}
if (currentFragment.mInfo.getNavigationBarConfig() != null) {
mNav.applyInfo(currentFragment.mInfo.getNavigationBarConfig());
} else {
mNav.applyInfo(new NavigationBarConfig(getString(R.string.flow_nav_bar_next),
getString(R.string.flow_nav_bar_previous),
currentIndex == 0 ? View.GONE : View.VISIBLE,
currentIndex >= (mPages.size() - 1) ? View.GONE : View.VISIBLE,
View.VISIBLE,
this,
this));
}
mHeader.applyInfo(currentFragment.mInfo.getHeaderConfig());
}
@Override
public void onClick(View v) {
final int currentIndex = mPager.getCurrentItem();
if (v.getId() == R.id.flow_nav_left_button) {
if (currentIndex > 0) previousFlow();
} else if (v.getId() == R.id.flow_nav_right_button) {
if (currentIndex < (mPages.size() - 1)) nextFlow();
}
}
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
if (getView() != null) return getView();
final View view = inflater.inflate(R.layout.fragment_flow, container, false);
mHeader = new Header(view.<ConstraintLayout>findViewById(R.id.flow_host_header));
mNav = new NavigationBar(view.<ConstraintLayout>findViewById(R.id.flow_host_nav));
mPager = view.findViewById(R.id.flow_host_pager);
mPager.setAdapter(new FragmentStatePagerAdapter(getChildFragmentManager()) {
@Override
public Fragment getItem(int position) {
return mPages.get(position);
}
@Override
public int getCount() {
return mPages.size();
}
});
mPager.addOnPageChangeListener(mPageListener);
return view;
}
@Override
public void onDestroyView() {
mPager.removeOnPageChangeListener(mPageListener);
super.onDestroyView();
}
@Override
public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
Log.d(TAG, "onViewCreated");
if (savedInstanceState != null) {
Log.d(TAG, "onViewCreated - restore " + savedInstanceState.getInt(ARG_CURRENT, -1));
mPager.setCurrentItem(savedInstanceState.getInt(ARG_CURRENT, 0));
}
if (mUIUpdateScheduled) {
updateUI();
mUIUpdateScheduled = false;
}
}
@Override
public void notifyCurrentFlowInfoUpdated() {
if (getView() != null) {
mUIUpdateScheduled = false;
updateUI();
} else {
mUIUpdateScheduled = true;
}
}
@Override
public void nextFlow() {
switchToFlow(mPager.getCurrentItem() + 1);
}
@Override
public void previousFlow() {
switchToFlow(mPager.getCurrentItem() - 1);
}
@Override
public int getFlowCount() {
return mPages.size();
}
@Override
public void switchToFlow(int index) {
mPager.setCurrentItem(index, true);
}
private ViewPager.OnPageChangeListener mPageListener = new ViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
notifyCurrentFlowInfoUpdated();
}
@Override
public void onPageScrollStateChanged(int state) {
}
};
/**
* @return true: the fragment handled this event and you do not need to call super. false: call super.
*/
public boolean onBackPressed() {
if (getView() == null) return false;
if (mPages.size() <= 0) return false;
final PageFragment pf = mPages.get(mPager.getCurrentItem());
if (pf != null) {
if (pf.onBackPressed()) return true;
}
// Default handling
if (mPager.getCurrentItem() == 0) return false;
mNav.getButton(NavigationBar.ButtonPosition.LEFT).performClick();
return true;
}
@Override
@NonNull
public View.OnClickListener getGeneralFlowNavListener() {
return this;
}
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// To save the child fragment instances
setRetainInstance(true);
}
@Override
public void onSaveInstanceState(@NonNull Bundle outState) {
super.onSaveInstanceState(outState);
Log.d(TAG, "save");
if (mPager != null) outState.putInt(ARG_CURRENT, mPager.getCurrentItem());
if (mPager != null) Log.d(TAG, "current " + mPager.getCurrentItem());
outState.putBoolean(ARG_UI_UPDATE_SCHEDULED, mUIUpdateScheduled);
}
@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
Log.d(TAG, "onActivityCreated");
if (savedInstanceState != null) {
Log.d(TAG, "restore");
mUIUpdateScheduled = savedInstanceState.getBoolean(ARG_UI_UPDATE_SCHEDULED, false);
}
}
}
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