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      1 /*
      2  * Copyright (C) 2012 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.inputmethod.keyboard.internal;
     18 
     19 import android.content.res.TypedArray;
     20 import android.graphics.Canvas;
     21 import android.graphics.Paint;
     22 import android.graphics.Paint.Align;
     23 import android.graphics.Rect;
     24 import android.graphics.RectF;
     25 import android.text.TextUtils;
     26 
     27 import com.android.inputmethod.keyboard.PointerTracker;
     28 import com.android.inputmethod.latin.R;
     29 import com.android.inputmethod.latin.SuggestedWords;
     30 import com.android.inputmethod.latin.common.CoordinateUtils;
     31 
     32 import javax.annotation.Nonnull;
     33 
     34 /**
     35  * The class for single gesture preview text. The class for multiple gesture preview text will be
     36  * derived from it.
     37  *
     38  * @attr ref R.styleable#KeyboardView_gestureFloatingPreviewTextSize
     39  * @attr ref R.styleable#KeyboardView_gestureFloatingPreviewTextColor
     40  * @attr ref R.styleable#KeyboardView_gestureFloatingPreviewTextOffset
     41  * @attr ref R.styleable#KeyboardView_gestureFloatingPreviewColor
     42  * @attr ref R.styleable#KeyboardView_gestureFloatingPreviewHorizontalPadding
     43  * @attr ref R.styleable#KeyboardView_gestureFloatingPreviewVerticalPadding
     44  * @attr ref R.styleable#KeyboardView_gestureFloatingPreviewRoundRadius
     45  */
     46 public class GestureFloatingTextDrawingPreview extends AbstractDrawingPreview {
     47     protected static final class GesturePreviewTextParams {
     48         public final int mGesturePreviewTextOffset;
     49         public final int mGesturePreviewTextHeight;
     50         public final float mGesturePreviewHorizontalPadding;
     51         public final float mGesturePreviewVerticalPadding;
     52         public final float mGesturePreviewRoundRadius;
     53         public final int mDisplayWidth;
     54 
     55         private final int mGesturePreviewTextSize;
     56         private final int mGesturePreviewTextColor;
     57         private final int mGesturePreviewColor;
     58         private final Paint mPaint = new Paint();
     59 
     60         private static final char[] TEXT_HEIGHT_REFERENCE_CHAR = { 'M' };
     61 
     62         public GesturePreviewTextParams(final TypedArray mainKeyboardViewAttr) {
     63             mGesturePreviewTextSize = mainKeyboardViewAttr.getDimensionPixelSize(
     64                     R.styleable.MainKeyboardView_gestureFloatingPreviewTextSize, 0);
     65             mGesturePreviewTextColor = mainKeyboardViewAttr.getColor(
     66                     R.styleable.MainKeyboardView_gestureFloatingPreviewTextColor, 0);
     67             mGesturePreviewTextOffset = mainKeyboardViewAttr.getDimensionPixelOffset(
     68                     R.styleable.MainKeyboardView_gestureFloatingPreviewTextOffset, 0);
     69             mGesturePreviewColor = mainKeyboardViewAttr.getColor(
     70                     R.styleable.MainKeyboardView_gestureFloatingPreviewColor, 0);
     71             mGesturePreviewHorizontalPadding = mainKeyboardViewAttr.getDimension(
     72                     R.styleable.MainKeyboardView_gestureFloatingPreviewHorizontalPadding, 0.0f);
     73             mGesturePreviewVerticalPadding = mainKeyboardViewAttr.getDimension(
     74                     R.styleable.MainKeyboardView_gestureFloatingPreviewVerticalPadding, 0.0f);
     75             mGesturePreviewRoundRadius = mainKeyboardViewAttr.getDimension(
     76                     R.styleable.MainKeyboardView_gestureFloatingPreviewRoundRadius, 0.0f);
     77             mDisplayWidth = mainKeyboardViewAttr.getResources().getDisplayMetrics().widthPixels;
     78 
     79             final Paint textPaint = getTextPaint();
     80             final Rect textRect = new Rect();
     81             textPaint.getTextBounds(TEXT_HEIGHT_REFERENCE_CHAR, 0, 1, textRect);
     82             mGesturePreviewTextHeight = textRect.height();
     83         }
     84 
     85         public Paint getTextPaint() {
     86             mPaint.setAntiAlias(true);
     87             mPaint.setTextAlign(Align.CENTER);
     88             mPaint.setTextSize(mGesturePreviewTextSize);
     89             mPaint.setColor(mGesturePreviewTextColor);
     90             return mPaint;
     91         }
     92 
     93         public Paint getBackgroundPaint() {
     94             mPaint.setColor(mGesturePreviewColor);
     95             return mPaint;
     96         }
     97     }
     98 
     99     private final GesturePreviewTextParams mParams;
    100     private final RectF mGesturePreviewRectangle = new RectF();
    101     private int mPreviewTextX;
    102     private int mPreviewTextY;
    103     private SuggestedWords mSuggestedWords = SuggestedWords.getEmptyInstance();
    104     private final int[] mLastPointerCoords = CoordinateUtils.newInstance();
    105 
    106     public GestureFloatingTextDrawingPreview(final TypedArray mainKeyboardViewAttr) {
    107         mParams = new GesturePreviewTextParams(mainKeyboardViewAttr);
    108     }
    109 
    110     @Override
    111     public void onDeallocateMemory() {
    112         // Nothing to do here.
    113     }
    114 
    115     public void dismissGestureFloatingPreviewText() {
    116         setSuggetedWords(SuggestedWords.getEmptyInstance());
    117     }
    118 
    119     public void setSuggetedWords(@Nonnull final SuggestedWords suggestedWords) {
    120         if (!isPreviewEnabled()) {
    121             return;
    122         }
    123         mSuggestedWords = suggestedWords;
    124         updatePreviewPosition();
    125     }
    126 
    127     @Override
    128     public void setPreviewPosition(final PointerTracker tracker) {
    129         if (!isPreviewEnabled()) {
    130             return;
    131         }
    132         tracker.getLastCoordinates(mLastPointerCoords);
    133         updatePreviewPosition();
    134     }
    135 
    136     /**
    137      * Draws gesture preview text
    138      * @param canvas The canvas where preview text is drawn.
    139      */
    140     @Override
    141     public void drawPreview(final Canvas canvas) {
    142         if (!isPreviewEnabled() || mSuggestedWords.isEmpty()
    143                 || TextUtils.isEmpty(mSuggestedWords.getWord(0))) {
    144             return;
    145         }
    146         final float round = mParams.mGesturePreviewRoundRadius;
    147         canvas.drawRoundRect(
    148                 mGesturePreviewRectangle, round, round, mParams.getBackgroundPaint());
    149         final String text = mSuggestedWords.getWord(0);
    150         canvas.drawText(text, mPreviewTextX, mPreviewTextY, mParams.getTextPaint());
    151     }
    152 
    153     /**
    154      * Updates gesture preview text position based on mLastPointerCoords.
    155      */
    156     protected void updatePreviewPosition() {
    157         if (mSuggestedWords.isEmpty() || TextUtils.isEmpty(mSuggestedWords.getWord(0))) {
    158             invalidateDrawingView();
    159             return;
    160         }
    161         final String text = mSuggestedWords.getWord(0);
    162 
    163         final RectF rectangle = mGesturePreviewRectangle;
    164 
    165         final int textHeight = mParams.mGesturePreviewTextHeight;
    166         final float textWidth = mParams.getTextPaint().measureText(text);
    167         final float hPad = mParams.mGesturePreviewHorizontalPadding;
    168         final float vPad = mParams.mGesturePreviewVerticalPadding;
    169         final float rectWidth = textWidth + hPad * 2.0f;
    170         final float rectHeight = textHeight + vPad * 2.0f;
    171 
    172         final float rectX = Math.min(
    173                 Math.max(CoordinateUtils.x(mLastPointerCoords) - rectWidth / 2.0f, 0.0f),
    174                 mParams.mDisplayWidth - rectWidth);
    175         final float rectY = CoordinateUtils.y(mLastPointerCoords)
    176                 - mParams.mGesturePreviewTextOffset - rectHeight;
    177         rectangle.set(rectX, rectY, rectX + rectWidth, rectY + rectHeight);
    178 
    179         mPreviewTextX = (int)(rectX + hPad + textWidth / 2.0f);
    180         mPreviewTextY = (int)(rectY + vPad) + textHeight;
    181         // TODO: Should narrow the invalidate region.
    182         invalidateDrawingView();
    183     }
    184 }
    185