content: /*
   * Copyright (C) 2013 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 License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.amnesica.kryptey.inputmethod.latin.utils;
  
  import android.graphics.Paint;
  import android.graphics.Rect;
  import android.graphics.Typeface;
  import android.util.SparseArray;
  
  public final class TypefaceUtils {
    private static final char[] KEY_LABEL_REFERENCE_CHAR = {'M'};
    private static final char[] KEY_NUMERIC_HINT_LABEL_REFERENCE_CHAR = {'8'};
  
    private TypefaceUtils() {
      // This utility class is not publicly instantiable.
    }
  
    // This sparse array caches key label text height in pixel indexed by key label text size.
    private static final SparseArray<Float> sTextHeightCache = new SparseArray<>();
    // Working variable for the following method.
    private static final Rect sTextHeightBounds = new Rect();
  
    private static float getCharHeight(final char[] referenceChar, final Paint paint) {
      final int key = getCharGeometryCacheKey(referenceChar[0], paint);
      synchronized (sTextHeightCache) {
        final Float cachedValue = sTextHeightCache.get(key);
        if (cachedValue != null) {
          return cachedValue;
        }
  
        paint.getTextBounds(referenceChar, 0, 1, sTextHeightBounds);
        final float height = sTextHeightBounds.height();
        sTextHeightCache.put(key, height);
        return height;
      }
    }
  
    // This sparse array caches key label text width in pixel indexed by key label text size.
    private static final SparseArray<Float> sTextWidthCache = new SparseArray<>();
    // Working variable for the following method.
    private static final Rect sTextWidthBounds = new Rect();
  
    private static float getCharWidth(final char[] referenceChar, final Paint paint) {
      final int key = getCharGeometryCacheKey(referenceChar[0], paint);
      synchronized (sTextWidthCache) {
        final Float cachedValue = sTextWidthCache.get(key);
        if (cachedValue != null) {
          return cachedValue;
        }
  
        paint.getTextBounds(referenceChar, 0, 1, sTextWidthBounds);
        final float width = sTextWidthBounds.width();
        sTextWidthCache.put(key, width);
        return width;
      }
    }
  
    private static int getCharGeometryCacheKey(final char referenceChar, final Paint paint) {
      final int labelSize = (int) paint.getTextSize();
      final Typeface face = paint.getTypeface();
      final int codePointOffset = referenceChar << 15;
      if (face == Typeface.DEFAULT) {
        return codePointOffset + labelSize;
      } else if (face == Typeface.DEFAULT_BOLD) {
        return codePointOffset + labelSize + 0x1000;
      } else if (face == Typeface.MONOSPACE) {
        return codePointOffset + labelSize + 0x2000;
      } else {
        return codePointOffset + labelSize;
      }
    }
  
    public static float getReferenceCharHeight(final Paint paint) {
      return getCharHeight(KEY_LABEL_REFERENCE_CHAR, paint);
    }
  
    public static float getReferenceCharWidth(final Paint paint) {
      return getCharWidth(KEY_LABEL_REFERENCE_CHAR, paint);
    }
  
    public static float getReferenceDigitWidth(final Paint paint) {
      return getCharWidth(KEY_NUMERIC_HINT_LABEL_REFERENCE_CHAR, paint);
    }
  
    // Working variable for the following method.
    private static final Rect sStringWidthBounds = new Rect();
  
    public static float getStringWidth(final String string, final Paint paint) {
      synchronized (sStringWidthBounds) {
        paint.getTextBounds(string, 0, string.length(), sStringWidthBounds);
        return sStringWidthBounds.width();
      }
    }
  }
  