super.onCreate(savedInstanceState);
setContentView(R.layout.linear_layout_listview_height);
mButton1 = findViewById(R.id.button1);
mButton2 = findViewById(R.id.button2);
mButton3 = findViewById(R.id.button3);
mOuterLayout = findViewById(R.id.layout);
mInnerList = (ListView)findViewById(R.id.inner_list);
mAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_dropdown_item_1line,
mStrings);
// Clicking this button will show the list view and set it to a fixed height
// If you then hide the views, there is no problem.
mButton1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// set listview to fixed height
ViewGroup.MarginLayoutParams lp;
lp = (ViewGroup.MarginLayoutParams) mInnerList.getLayoutParams();
lp.height = 200;
mInnerList.setLayoutParams(lp);
// enable list adapter
mInnerList.setAdapter(mAdapter);
// and show it
mOuterLayout.setVisibility(View.VISIBLE);
}
});
// Clicking this button will show the list view and set it match_parent height
// If you then hide the views, there is an NPE when calculating the ListView height.
mButton2.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// set listview to fill screen
ViewGroup.MarginLayoutParams lp;
lp = (ViewGroup.MarginLayoutParams) mInnerList.getLayoutParams();
lp.height = lp.MATCH_PARENT;
mInnerList.setLayoutParams(lp);
// enable list adapter
mInnerList.setAdapter(mAdapter);
// and show it
mOuterLayout.setVisibility(View.VISIBLE);
}
});
// Clicking this button will remove the list adapter and hide the outer enclosing view.
// We have to climb all the way to the top because the bug (not checking visibility)
// only occurs at the very outer loop of ViewAncestor.performTraversals and in the case of
// an Activity, this means you have to crawl all the way out to the root view.
// In the search manager, it's sufficient to simply show/hide the outer search manager
// view to trigger the same bug.
mButton3.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
mInnerList.setAdapter(null);
// hide listview's owner
// as it turns out, the owner doesn't take us high enough
// because our activity includes a title bar, thus another layer
View parent = (View) mOuterLayout.getParent(); // FrameLayout (app container)
View grandpa = (View) parent.getParent(); // LinearLayout (title+app)
View great = (View) grandpa.getParent(); // PhoneWindow.DecorView
great.setVisibility(View.GONE);
}
});
