Implement CandidateView using HorizontalScrollView

This change re-implements CandidateView using HorizontalScrollView and
customized Button, so that the candidate strip can be flingable.

This change also introduces the following features.

- Highlighting candidate strip and space bar is configurable by
  @bool/config_candidate_highlight_enabled.
- Candidate strip can be centered with left/right padding if
  @dimen/candidate_strip_padding size is greater than 0.
- Candidate text size is configurable by @dimen/candidate_text_size.

Bug: 1575885
Bug: 3230726
Change-Id: Iedf78ff31bc9f2f6291a8e8fb7faa0e6b961dd6d

2 files changed, 146 insertions, 357 deletions

diff --git a/java/src/com/android/inputmethod/latin/CandidateView.java b/java/src/com/android/inputmethod/latin/CandidateView.java
index 68f288925..460ef8650 100644
--- a/java/src/com/android/inputmethod/latin/CandidateView.java
+++ b/java/src/com/android/inputmethod/latin/CandidateView.java
@@ -1,12 +1,12 @@
 /*
- * Copyright (C) 2008 The Android Open Source Project
- * 
+ * Copyright (C) 2010 The Android Open Source Project
+ *
  * 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
@@ -18,75 +18,55 @@ package com.android.inputmethod.latin;
 
 import android.content.Context;
 import android.content.res.Resources;
-import android.graphics.Canvas;
-import android.graphics.Paint;
-import android.graphics.Paint.Align;
-import android.graphics.Rect;
 import android.graphics.Typeface;
-import android.graphics.drawable.Drawable;
+import android.os.Handler;
+import android.os.Message;
+import android.text.TextUtils;
 import android.util.AttributeSet;
-import android.view.GestureDetector;
 import android.view.Gravity;
 import android.view.LayoutInflater;
-import android.view.MotionEvent;
 import android.view.View;
-import android.view.ViewGroup.LayoutParams;
+import android.view.View.OnClickListener;
+import android.view.View.OnLongClickListener;
+import android.widget.ImageView;
+import android.widget.LinearLayout;
 import android.widget.PopupWindow;
 import android.widget.TextView;
 
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.List;
 
-public class CandidateView extends View {
-
-    private static final int OUT_OF_BOUNDS_WORD_INDEX = -1;
-    private static final int OUT_OF_BOUNDS_X_COORD = -1;
-
+public class CandidateView extends LinearLayout implements OnClickListener, OnLongClickListener {
     private LatinIME mService;
     private final ArrayList<CharSequence> mSuggestions = new ArrayList<CharSequence>();
-    private boolean mShowingCompletions;
-    private CharSequence mSelectedString;
-    private int mSelectedIndex;
-    private int mTouchX = OUT_OF_BOUNDS_X_COORD;
-    private final Drawable mSelectionHighlight;
-    private boolean mTypedWordValid;
-    
-    private boolean mHaveMinimalSuggestion;
-    
-    private Rect mBgPadding;
+    private final ArrayList<View> mWords = new ArrayList<View>();
 
     private final TextView mPreviewText;
     private final PopupWindow mPreviewPopup;
-    private int mCurrentWordIndex;
-    private Drawable mDivider;
-    
-    private static final int MAX_SUGGESTIONS = 32;
-    private static final int SCROLL_PIXELS = 20;
     
-    private final int[] mWordWidth = new int[MAX_SUGGESTIONS];
-    private final int[] mWordX = new int[MAX_SUGGESTIONS];
-    private int mPopupPreviewX;
-    private int mPopupPreviewY;
+    private static final int MAX_SUGGESTIONS = 16;
 
-    private static final int X_GAP = 10;
-    
+    private final boolean mConfigCandidateHighlightFontColorEnabled;
     private final int mColorNormal;
     private final int mColorRecommended;
     private final int mColorOther;
-    private final Paint mPaint;
-    private final int mDescent;
-    private boolean mScrolled;
-    private boolean mShowingAddToDictionary;
-    private CharSequence mAddToDictionaryHint;
 
-    private int mTargetScrollX;
+    private boolean mShowingCompletions;
 
-    private final int mMinTouchableWidth;
+    private boolean mShowingAddToDictionary;
 
-    private int mTotalWidth;
-    
-    private final GestureDetector mGestureDetector;
+    private static final long DELAY_HIDE_PREVIEW = 1000;
+    private static final int MSG_HIDE_PREVIEW = 0;
+    private final Handler mHandler = new Handler() {
+        @Override
+        public void dispatchMessage(Message msg) {
+            switch (msg.what) {
+            case MSG_HIDE_PREVIEW:
+                hidePreview();
+                break;
+            }
+        }
+    };
 
     /**
      * Construct a CandidateView for showing suggested words for completion.
@@ -95,95 +75,35 @@ public class CandidateView extends View {
      */
     public CandidateView(Context context, AttributeSet attrs) {
         super(context, attrs);
-        mSelectionHighlight = context.getResources().getDrawable(
-                R.drawable.list_selector_background_pressed);
 
-        LayoutInflater inflate =
-            (LayoutInflater) context
-                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
         Resources res = context.getResources();
         mPreviewPopup = new PopupWindow(context);
-        mPreviewText = (TextView) inflate.inflate(R.layout.candidate_preview, null);
+        LayoutInflater inflater = LayoutInflater.from(context);
+        mPreviewText = (TextView) inflater.inflate(R.layout.candidate_preview, null);
         mPreviewPopup.setWindowLayoutMode(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
         mPreviewPopup.setContentView(mPreviewText);
         mPreviewPopup.setBackgroundDrawable(null);
         mPreviewPopup.setAnimationStyle(R.style.KeyPreviewAnimation);
+        mConfigCandidateHighlightFontColorEnabled =
+                res.getBoolean(R.bool.config_candidate_highlight_font_color_enabled);
         mColorNormal = res.getColor(R.color.candidate_normal);
         mColorRecommended = res.getColor(R.color.candidate_recommended);
         mColorOther = res.getColor(R.color.candidate_other);
-        mDivider = res.getDrawable(R.drawable.keyboard_suggest_strip_divider);
-        mAddToDictionaryHint = res.getString(R.string.hint_add_to_dictionary);
 
-        mPaint = new Paint();
-        mPaint.setColor(mColorNormal);
-        mPaint.setAntiAlias(true);
-        mPaint.setTextSize(mPreviewText.getTextSize());
-        mPaint.setStrokeWidth(0);
-        mPaint.setTextAlign(Align.CENTER);
-        mDescent = (int) mPaint.descent();
-        mMinTouchableWidth = (int)res.getDimension(R.dimen.candidate_min_touchable_width);
-        
-        mGestureDetector = new GestureDetector(
-                new CandidateStripGestureListener(mMinTouchableWidth));
-        setWillNotDraw(false);
-        setHorizontalScrollBarEnabled(false);
-        setVerticalScrollBarEnabled(false);
-        scrollTo(0, getScrollY());
-    }
-
-    private class CandidateStripGestureListener extends GestureDetector.SimpleOnGestureListener {
-        private final int mTouchSlopSquare;
-
-        public CandidateStripGestureListener(int touchSlop) {
-            // Slightly reluctant to scroll to be able to easily choose the suggestion
-            mTouchSlopSquare = touchSlop * touchSlop;
-        }
-
-        @Override
-        public void onLongPress(MotionEvent me) {
-            if (mSuggestions.size() > 0) {
-                if (me.getX() + getScrollX() < mWordWidth[0] && getScrollX() < 10) {
-                    longPressFirstWord();
-                }
-            }
+        for (int i = 0; i < MAX_SUGGESTIONS; i++) {
+            View v = inflater.inflate(R.layout.candidate, null);
+            TextView tv = (TextView)v.findViewById(R.id.candidate_word);
+            tv.setTag(i);
+            tv.setOnClickListener(this);
+            if (i == 0)
+                tv.setOnLongClickListener(this);
+            ImageView divider = (ImageView)v.findViewById(R.id.candidate_divider);
+            // Do not display divider of first candidate.
+            divider.setVisibility(i == 0 ? View.GONE : View.VISIBLE);
+            mWords.add(v);
         }
 
-        @Override
-        public boolean onDown(MotionEvent e) {
-            mScrolled = false;
-            return false;
-        }
-
-        @Override
-        public boolean onScroll(MotionEvent e1, MotionEvent e2,
-                float distanceX, float distanceY) {
-            if (!mScrolled) {
-                // This is applied only when we recognize that scrolling is starting.
-                final int deltaX = (int) (e2.getX() - e1.getX());
-                final int deltaY = (int) (e2.getY() - e1.getY());
-                final int distance = (deltaX * deltaX) + (deltaY * deltaY);
-                if (distance < mTouchSlopSquare) {
-                    return true;
-                }
-                mScrolled = true;
-            }
-
-            final int width = getWidth();
-            mScrolled = true;
-            int scrollX = getScrollX();
-            scrollX += (int) distanceX;
-            if (scrollX < 0) {
-                scrollX = 0;
-            }
-            if (distanceX > 0 && scrollX + width > mTotalWidth) {
-                scrollX -= (int) distanceX;
-            }
-            mTargetScrollX = scrollX;
-            scrollTo(scrollX, getScrollY());
-            hidePreview();
-            invalidate();
-            return true;
-        }
+        scrollTo(0, getScrollY());
     }
 
     /**
@@ -193,145 +113,56 @@ public class CandidateView extends View {
     public void setService(LatinIME listener) {
         mService = listener;
     }
-    
-    @Override
-    public int computeHorizontalScrollRange() {
-        return mTotalWidth;
-    }
 
-    /**
-     * If the canvas is null, then only touch calculations are performed to pick the target
-     * candidate.
-     */
-    @Override
-    protected void onDraw(Canvas canvas) {
-        if (canvas != null) {
-            super.onDraw(canvas);
-        }
-        mTotalWidth = 0;
-        
-        final int height = getHeight();
-        if (mBgPadding == null) {
-            mBgPadding = new Rect(0, 0, 0, 0);
-            if (getBackground() != null) {
-                getBackground().getPadding(mBgPadding);
+    public void setSuggestions(List<CharSequence> suggestions, boolean completions,
+            boolean typedWordValid, boolean haveMinimalSuggestion) {
+        clear();
+        if (suggestions != null) {
+            int insertCount = Math.min(suggestions.size(), MAX_SUGGESTIONS);
+            for (CharSequence suggestion : suggestions) {
+                mSuggestions.add(suggestion);
+                if (--insertCount == 0)
+                    break;
             }
-            mDivider.setBounds(0, 0, mDivider.getIntrinsicWidth(),
-                    mDivider.getIntrinsicHeight());
         }
 
         final int count = mSuggestions.size();
-        final Rect bgPadding = mBgPadding;
-        final Paint paint = mPaint;
-        final int touchX = mTouchX;
-        final int scrollX = getScrollX();
-        final boolean scrolled = mScrolled;
-        final boolean typedWordValid = mTypedWordValid;
-        final int y = (int) (height + mPaint.getTextSize() - mDescent) / 2;
-
         boolean existsAutoCompletion = false;
 
-        int x = 0;
         for (int i = 0; i < count; i++) {
             CharSequence suggestion = mSuggestions.get(i);
             if (suggestion == null) continue;
             final int wordLength = suggestion.length();
 
-            paint.setColor(mColorNormal);
-            if (mHaveMinimalSuggestion 
-                    && ((i == 1 && !typedWordValid) || (i == 0 && typedWordValid))) {
-                paint.setTypeface(Typeface.DEFAULT_BOLD);
-                paint.setColor(mColorRecommended);
-                existsAutoCompletion = true;
-            } else if (i != 0 || (wordLength == 1 && count > 1)) {
-                // HACK: even if i == 0, we use mColorOther when this suggestion's length is 1 and
-                // there are multiple suggestions, such as the default punctuation list.
-                paint.setColor(mColorOther);
-            }
-            int wordWidth;
-            if ((wordWidth = mWordWidth[i]) == 0) {
-                float textWidth =  paint.measureText(suggestion, 0, wordLength);
-                wordWidth = Math.max(mMinTouchableWidth, (int) textWidth + X_GAP * 2);
-                mWordWidth[i] = wordWidth;
-            }
-
-            mWordX[i] = x;
-
-            if (touchX != OUT_OF_BOUNDS_X_COORD && !scrolled
-                    && touchX + scrollX >= x && touchX + scrollX < x + wordWidth) {
-                if (canvas != null && !mShowingAddToDictionary) {
-                    canvas.translate(x, 0);
-                    mSelectionHighlight.setBounds(0, bgPadding.top, wordWidth, height);
-                    mSelectionHighlight.draw(canvas);
-                    canvas.translate(-x, 0);
+            View v = mWords.get(i);
+            TextView tv = (TextView)v.findViewById(R.id.candidate_word);
+            tv.setTypeface(Typeface.DEFAULT);
+            tv.setTextColor(mColorNormal);
+            if (mConfigCandidateHighlightFontColorEnabled) {
+                if (haveMinimalSuggestion
+                        && ((i == 1 && !typedWordValid) || (i == 0 && typedWordValid))) {
+                    tv.setTypeface(Typeface.DEFAULT_BOLD);
+                    tv.setTextColor(mColorRecommended);
+                    existsAutoCompletion = true;
+                } else if (i != 0 || (wordLength == 1 && count > 1)) {
+                    // HACK: even if i == 0, we use mColorOther when this suggestion's length is 1
+                    // and there are multiple suggestions, such as the default punctuation list.
+                    tv.setTextColor(mColorOther);
                 }
-                mSelectedString = suggestion;
-                mSelectedIndex = i;
-            }
-
-            if (canvas != null) {
-                canvas.drawText(suggestion, 0, wordLength, x + wordWidth / 2, y, paint);
-                paint.setColor(mColorOther);
-                canvas.translate(x + wordWidth, 0);
-                // Draw a divider unless it's after the hint
-                if (!(mShowingAddToDictionary && i == 1)) {
-                    mDivider.draw(canvas);
-                }
-                canvas.translate(-x - wordWidth, 0);
-            }
-            paint.setTypeface(Typeface.DEFAULT);
-            x += wordWidth;
-        }
-        mService.onAutoCompletionStateChanged(existsAutoCompletion);
-        mTotalWidth = x;
-        if (mTargetScrollX != scrollX) {
-            scrollToTarget();
-        }
-    }
-    
-    private void scrollToTarget() {
-        int scrollX = getScrollX();
-        if (mTargetScrollX > scrollX) {
-            scrollX += SCROLL_PIXELS;
-            if (scrollX >= mTargetScrollX) {
-                scrollX = mTargetScrollX;
-                scrollTo(scrollX, getScrollY());
-                requestLayout();
             } else {
-                scrollTo(scrollX, getScrollY());
-            }
-        } else {
-            scrollX -= SCROLL_PIXELS;
-            if (scrollX <= mTargetScrollX) {
-                scrollX = mTargetScrollX;
-                scrollTo(scrollX, getScrollY());
-                requestLayout();
-            } else {
-                scrollTo(scrollX, getScrollY());
-            }
-        }
-        invalidate();
-    }
-    
-    public void setSuggestions(List<CharSequence> suggestions, boolean completions,
-            boolean typedWordValid, boolean haveMinimalSuggestion) {
-        clear();
-        if (suggestions != null) {
-            int insertCount = Math.min(suggestions.size(), MAX_SUGGESTIONS);
-            for (CharSequence suggestion : suggestions) {
-                mSuggestions.add(suggestion);
-                if (--insertCount == 0)
-                    break;
+                // TODO: Display underline for the auto-correction word
             }
+            tv.setText(suggestion);
+            tv.setClickable(true);
+            addView(v);
         }
+
         mShowingCompletions = completions;
-        mTypedWordValid = typedWordValid;
+        // TODO: Move this call back to LatinIME
+        if (mConfigCandidateHighlightFontColorEnabled)
+            mService.onAutoCompletionStateChanged(existsAutoCompletion);
+
         scrollTo(0, getScrollY());
-        mTargetScrollX = 0;
-        mHaveMinimalSuggestion = haveMinimalSuggestion;
-        // Compute the total width
-        onDraw(null);
-        invalidate();
         requestLayout();
     }
 
@@ -342,9 +173,12 @@ public class CandidateView extends View {
     public void showAddToDictionaryHint(CharSequence word) {
         ArrayList<CharSequence> suggestions = new ArrayList<CharSequence>();
         suggestions.add(word);
-        suggestions.add(mAddToDictionaryHint);
+        suggestions.add(getContext().getText(R.string.hint_add_to_dictionary));
         setSuggestions(suggestions, false, false, false);
         mShowingAddToDictionary = true;
+        // Disable R.string.hint_add_to_dictionary button
+        TextView tv = (TextView)getChildAt(1).findViewById(R.id.candidate_word);
+        tv.setClickable(false);
     }
 
     public boolean dismissAddToDictionaryHint() {
@@ -361,127 +195,72 @@ public class CandidateView extends View {
         // Don't call mSuggestions.clear() because it's being used for logging
         // in LatinIME.pickSuggestionManually().
         mSuggestions.clear();
-        mTouchX = OUT_OF_BOUNDS_X_COORD;
-        mSelectedString = null;
-        mSelectedIndex = -1;
         mShowingAddToDictionary = false;
-        invalidate();
-        Arrays.fill(mWordWidth, 0);
-        Arrays.fill(mWordX, 0);
-    }
-    
-    @Override
-    public boolean onTouchEvent(MotionEvent me) {
-
-        if (mGestureDetector.onTouchEvent(me)) {
-            return true;
-        }
-
-        int action = me.getAction();
-        int x = (int) me.getX();
-        int y = (int) me.getY();
-        mTouchX = x;
-
-        switch (action) {
-        case MotionEvent.ACTION_DOWN:
-            invalidate();
-            break;
-        case MotionEvent.ACTION_MOVE:
-            if (y <= 0) {
-                // Fling up!?
-                if (mSelectedString != null) {
-                    // If there are completions from the application, we don't change the state to
-                    // STATE_PICKED_SUGGESTION
-                    if (!mShowingCompletions) {
-                        // This "acceptedSuggestion" will not be counted as a word because
-                        // it will be counted in pickSuggestion instead.
-                        TextEntryState.acceptedSuggestion(mSuggestions.get(0),
-                                mSelectedString);
-                    }
-                    mService.pickSuggestionManually(mSelectedIndex, mSelectedString);
-                    mSelectedString = null;
-                    mSelectedIndex = -1;
-                }
-            }
-            break;
-        case MotionEvent.ACTION_UP:
-            if (!mScrolled) {
-                if (mSelectedString != null) {
-                    if (mShowingAddToDictionary) {
-                        longPressFirstWord();
-                        clear();
-                    } else {
-                        if (!mShowingCompletions) {
-                            TextEntryState.acceptedSuggestion(mSuggestions.get(0),
-                                    mSelectedString);
-                        }
-                        mService.pickSuggestionManually(mSelectedIndex, mSelectedString);
-                    }
-                }
-            }
-            mSelectedString = null;
-            mSelectedIndex = -1;
-            requestLayout();
-            hidePreview();
-            invalidate();
-            break;
-        }
-        return true;
+        removeAllViews();
     }
 
     private void hidePreview() {
-        mTouchX = OUT_OF_BOUNDS_X_COORD;
-        mCurrentWordIndex = OUT_OF_BOUNDS_WORD_INDEX;
         mPreviewPopup.dismiss();
     }
-    
-    private void showPreview(int wordIndex, String altText) {
-        int oldWordIndex = mCurrentWordIndex;
-        mCurrentWordIndex = wordIndex;
-        // If index changed or changing text
-        if (oldWordIndex != mCurrentWordIndex || altText != null) {
-            if (wordIndex == OUT_OF_BOUNDS_WORD_INDEX) {
-                hidePreview();
-            } else {
-                CharSequence word = altText != null? altText : mSuggestions.get(wordIndex);
-                mPreviewText.setText(word);
-                mPreviewText.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 
-                        MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
-                int wordWidth = (int) (mPaint.measureText(word, 0, word.length()) + X_GAP * 2);
-                final int popupWidth = wordWidth
-                        + mPreviewText.getPaddingLeft() + mPreviewText.getPaddingRight();
-                final int popupHeight = mPreviewText.getMeasuredHeight();
-                //mPreviewText.setVisibility(INVISIBLE);
-                mPopupPreviewX = mWordX[wordIndex] - mPreviewText.getPaddingLeft() - getScrollX()
-                        + (mWordWidth[wordIndex] - wordWidth) / 2;
-                mPopupPreviewY = - popupHeight;
-                int [] offsetInWindow = new int[2];
-                getLocationInWindow(offsetInWindow);
-                if (mPreviewPopup.isShowing()) {
-                    mPreviewPopup.update(mPopupPreviewX, mPopupPreviewY + offsetInWindow[1], 
-                            popupWidth, popupHeight);
-                } else {
-                    mPreviewPopup.setWidth(popupWidth);
-                    mPreviewPopup.setHeight(popupHeight);
-                    mPreviewPopup.showAtLocation(this, Gravity.NO_GRAVITY, mPopupPreviewX, 
-                            mPopupPreviewY + offsetInWindow[1]);
-                }
-                mPreviewText.setVisibility(VISIBLE);
-            }
+
+    private void showPreview(int index, CharSequence word) {
+        if (TextUtils.isEmpty(word))
+            return;
+
+        final TextView previewText = mPreviewText;
+        previewText.setText(word);
+        previewText.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED),
+                MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
+        View v = getChildAt(index);
+        final int[] offsetInWindow = new int[2];
+        v.getLocationInWindow(offsetInWindow);
+        final int posX = offsetInWindow[0];
+        final int posY = offsetInWindow[1] - previewText.getMeasuredHeight();
+        final PopupWindow previewPopup = mPreviewPopup;
+        if (previewPopup.isShowing()) {
+            previewPopup.update(posX, posY, previewPopup.getWidth(), previewPopup.getHeight());
+        } else {
+            previewPopup.showAtLocation(this, Gravity.NO_GRAVITY, posX, posY);
         }
+        previewText.setVisibility(VISIBLE);
+        mHandler.sendMessageDelayed(
+                mHandler.obtainMessage(MSG_HIDE_PREVIEW), DELAY_HIDE_PREVIEW);
     }
 
-    private void longPressFirstWord() {
-        CharSequence word = mSuggestions.get(0);
-        if (word.length() < 2) return;
+    private void addToDictionary(CharSequence word) {
         if (mService.addWordToDictionary(word.toString())) {
-            showPreview(0, getContext().getResources().getString(R.string.added_word, word));
+            showPreview(0, getContext().getString(R.string.added_word, word));
+        }
+    }
+
+    @Override
+    public boolean onLongClick(View view) {
+        int index = (Integer) view.getTag();
+        CharSequence word = mSuggestions.get(index);
+        if (word.length() < 2)
+            return false;
+        addToDictionary(word);
+        return true;
+    }
+
+    @Override
+    public void onClick(View view) {
+        int index = (Integer) view.getTag();
+        CharSequence word = mSuggestions.get(index);
+        if (mShowingAddToDictionary && index == 0) {
+            addToDictionary(word);
+        } else {
+            if (!mShowingCompletions) {
+                TextEntryState.acceptedSuggestion(mSuggestions.get(0), word);
+            }
+            mService.pickSuggestionManually(index, word);
         }
     }
     
     @Override
     public void onDetachedFromWindow() {
         super.onDetachedFromWindow();
+        mHandler.removeMessages(MSG_HIDE_PREVIEW);
         hidePreview();
     }
 }
diff --git a/java/src/com/android/inputmethod/latin/LatinIME.java b/java/src/com/android/inputmethod/latin/LatinIME.java
index 3089153ad..16a369a9e 100644
--- a/java/src/com/android/inputmethod/latin/LatinIME.java
+++ b/java/src/com/android/inputmethod/latin/LatinIME.java
@@ -51,8 +51,10 @@ import android.util.DisplayMetrics;
 import android.util.Log;
 import android.util.PrintWriterPrinter;
 import android.util.Printer;
+import android.view.Gravity;
 import android.view.HapticFeedbackConstants;
 import android.view.KeyEvent;
+import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.ViewParent;
@@ -65,6 +67,7 @@ import android.view.inputmethod.ExtractedTextRequest;
 import android.view.inputmethod.InputConnection;
 import android.view.inputmethod.InputMethodManager;
 import android.view.inputmethod.InputMethodSubtype;
+import android.widget.HorizontalScrollView;
 import android.widget.LinearLayout;
 
 import java.io.FileDescriptor;
@@ -127,7 +130,7 @@ public class LatinIME extends InputMethodService
         SUGGESTION_VISIBILILTY_HIDE_VALUE
     };
 
-    private LinearLayout mCandidateViewContainer;
+    private View mCandidateViewContainer;
     private CandidateView mCandidateView;
     private Suggest mSuggest;
     private CompletionInfo[] mCompletions;
@@ -496,12 +499,19 @@ public class LatinIME extends InputMethodService
 
     @Override
     public View onCreateCandidatesView() {
-        mCandidateViewContainer = (LinearLayout) getLayoutInflater().inflate(
-                R.layout.candidates, null);
-        mCandidateView = (CandidateView) mCandidateViewContainer.findViewById(R.id.candidates);
+        LayoutInflater inflater = getLayoutInflater();
+        LinearLayout container = (LinearLayout)inflater.inflate(R.layout.candidates, null);
+        mCandidateViewContainer = container;
+        if (container.getPaddingRight() != 0) {
+            HorizontalScrollView scrollView =
+                    (HorizontalScrollView) container.findViewById(R.id.candidates_scroll_view);
+            scrollView.setOverScrollMode(View.OVER_SCROLL_NEVER);
+            container.setGravity(Gravity.CENTER_HORIZONTAL);
+        }
+        mCandidateView = (CandidateView) container.findViewById(R.id.candidates);
         mCandidateView.setService(this);
         setCandidatesViewShown(true);
-        return mCandidateViewContainer;
+        return container;
     }
 
     private static boolean isPasswordVariation(int variation) {