Making suggestion popup scrollable in landscape mode

chrome/android/shell/java/src/org/chromium/chrome/shell/omnibox/SuggestionPopup.java

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chrome.shell.omnibox;
 
 import android.content.Context;
+import android.graphics.Rect;
 import android.os.Handler;
 import android.text.Editable;
 import android.text.TextUtils;
 import android.text.TextWatcher;
 import android.view.View;
 import android.view.View.OnLayoutChangeListener;
 import android.widget.AdapterView;
 import android.widget.AdapterView.OnItemClickListener;
 import android.widget.ListPopupWindow;
 import android.widget.PopupWindow.OnDismissListener;
 import android.widget.TextView;
 
 import org.chromium.chrome.browser.omnibox.AutocompleteController;
 import org.chromium.chrome.browser.omnibox.AutocompleteController.OnSuggestionsReceivedListener;
 import org.chromium.chrome.browser.omnibox.OmniboxSuggestion;
+import org.chromium.chrome.shell.ChromeShellActivity;
 import org.chromium.chrome.shell.ChromeShellToolbar;
 import org.chromium.chrome.shell.R;
 
 import java.util.List;
 
 /**
  * Displays suggestions for the text that is entered to the ChromeShell URL field.
  */
 public class SuggestionPopup implements OnSuggestionsReceivedListener, TextWatcher {
     private static final long SUGGESTION_START_DELAY_MS = 30;
 
     private final Context mContext;
     private final TextView mUrlField;
     private final ChromeShellToolbar mToolbar;
     private final AutocompleteController mAutocomplete;
 
     private boolean mHasStartedNewOmniboxEditSession;
     private Runnable mRequestSuggestions;
     private ListPopupWindow mSuggestionsPopup;
     private SuggestionArrayAdapter mSuggestionArrayAdapter;
+    private int mSuggestionsPopupItemsCount;
 
     /**
      * Initializes a suggestion popup that will track urlField value and display suggestions based
      * on that value.
      */
     public SuggestionPopup(Context context, TextView urlField,
             ChromeShellToolbar toolbar) {
         mContext = context;
         mUrlField = urlField;
         mToolbar = toolbar;
         mAutocomplete = new AutocompleteController(this);
         OnLayoutChangeListener listener = new OnLayoutChangeListener() {
             @Override
             public void onLayoutChange(View v, int left, int top, int right, int bottom,
                     int oldLeft, int oldTop, int oldRight, int oldBottom) {
                 if (mSuggestionsPopup == null || !mSuggestionsPopup.isShowing()) return;
                 mSuggestionsPopup.setWidth(mUrlField.getWidth());
+                mSuggestionsPopup.setHeight(getSuggestionPopupHeight());
                 mSuggestionsPopup.show();
             }
         };
         mUrlField.addOnLayoutChangeListener(listener);
     }
 
     private void navigateToSuggestion(int position) {
         mToolbar.getCurrentTab().loadUrlWithSanitization(
                 mSuggestionArrayAdapter.getItem(position).getUrl());
         mUrlField.clearFocus();
@@ skipping 21 matching lines @@
      * Signals the autocomplete controller to stop generating suggestions and
      * cancels the queued task to start the autocomplete controller, if any.
      *
      * @param clear Whether to clear the most recent autocomplete results.
      */
     private void stopAutocomplete(boolean clear) {
         if (mAutocomplete != null) mAutocomplete.stop(clear);
         if (mRequestSuggestions != null) mRequestSuggestions = null;
     }
 
+    private int getSuggestionPopupHeight() {
+        Rect appRect = new Rect();
+        ((ChromeShellActivity)mContext).getWindow().getDecorView().
+                getWindowVisibleDisplayFrame(appRect);
+        int dropDownItemHeight = mContext.getResources().
+                getDimensionPixelSize(R.dimen.dropdown_item_height);
+        int popupHeight = appRect.height();
+        if (mSuggestionsPopup != null) {
+            int height = dropDownItemHeight;

[Bernhard Bauer, 2014/09/02 08:54:15]

This assignment is unnecessary.

[ankit, 2014/09/02 09:23:04]

Done.

+            height = mSuggestionsPopupItemsCount * dropDownItemHeight;
+            if (height < appRect.height())

[Bernhard Bauer, 2014/09/02 08:54:15]

You could use popupHeight instead of appRect.height() here, which would IMO make
it clearer that you're using the smaller one out of the two values.

[ankit, 2014/09/02 09:23:04]

Done.

+                popupHeight = height;
+        }
+        // Maintaining margin height equal to |dropDownItemHeight|.
+        return (popupHeight - dropDownItemHeight > 0) ?
+                (popupHeight - dropDownItemHeight) : popupHeight;

[Bernhard Bauer, 2014/09/02 08:54:15]

There's still a discontinuity here: As |popupHeight| gets smaller, the returned
value goes down until it reaches zero, then it jumps up again to |popupHeight|.
Would it make sense to clamp at 0 instead? Then you could just write this as
Math.max(popupHeight - dropDownItemHeight, 0) and avoid having `popupHeight -
dropDownItemHeight` twice.

(If we keep the logic as it currently is, I'd still suggest extracting that
value to a local variable).

[ankit, 2014/09/02 09:23:04]

As per current logic when number of suggestion item is one, In that case
maintaining margin will make popup height zero. Avoiding that case with this
check. Problem will not be solved by clamping at 0 as in that case height should
not be 0. 
Please suggest if we can achieve same in better way.

[Bernhard Bauer, 2014/09/02 09:31:01]

Hm, now that I think about it, doesn't the margin only apply when we're
constrained by the app rect? That is, when the popup is big, we want it not to
be bigger than the app rect (lines 115-116), and on top of that we want to have
a margin too. If that is correct, then we should apply the margin when comparing
to the app rect, i.e. in line 111 or so. Or am I misunderstanding the behavior
you want to achieve here?

+    }
+
     // OnSuggestionsReceivedListener implementation
-
     @Override
     public void onSuggestionsReceived(List<OmniboxSuggestion> suggestions,
             String inlineAutocompleteText) {
         if (!mUrlField.isFocused() || suggestions.isEmpty())
             return;
+        mSuggestionsPopupItemsCount = suggestions.size();
         if (mSuggestionsPopup == null) {
             mSuggestionsPopup = new ListPopupWindow(
                     mContext, null, android.R.attr.autoCompleteTextViewStyle);
             mSuggestionsPopup.setOnDismissListener(new OnDismissListener() {
                 @Override
                 public void onDismiss() {
                     mHasStartedNewOmniboxEditSession = false;
                     mSuggestionArrayAdapter = null;
                 }
             });
         }
+        mSuggestionsPopup.setInputMethodMode(ListPopupWindow.INPUT_METHOD_NEEDED);
         mSuggestionsPopup.setWidth(mUrlField.getWidth());
         mSuggestionArrayAdapter =
                 new SuggestionArrayAdapter(mContext, R.layout.dropdown_item, suggestions);
+        mSuggestionsPopup.setHeight(getSuggestionPopupHeight());
         mSuggestionsPopup.setAdapter(mSuggestionArrayAdapter);
         mSuggestionsPopup.setAnchorView(mUrlField);
         mSuggestionsPopup.setOnItemClickListener(new OnItemClickListener() {
             @Override
             public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                 navigateToSuggestion(position);
             }
         });
         mSuggestionsPopup.show();
     }
@@ skipping 29 matching lines @@
 
     @Override
     public void beforeTextChanged(CharSequence s, int start, int count, int after) {
         mRequestSuggestions = null;
     }
 
     @Override
     public void onTextChanged(CharSequence s, int start, int before, int count) {
     }
 }