core/java/android/text/TextPaint.java

/*
 * Copyright (C) 2006 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 android.text;

import android.annotation.ColorInt;
import android.annotation.NonNull;
import android.graphics.Paint;

/**
 * TextPaint is an extension of Paint that leaves room for some extra
 * data used during text measuring and drawing.
 */
public class TextPaint extends Paint {

    // Special value 0 means no background paint
    @ColorInt
    public int bgColor;
    public int baselineShift;
    @ColorInt
    public int linkColor;
    public int[] drawableState;
    public float density = 1.0f;
    /**
     * Special value 0 means no custom underline
     * @hide
     */
    @ColorInt
    public int underlineColor = 0;
    /**
     * Thickness of the underline, in pixels.
     * @hide
     */
    public float underlineThickness;

    public TextPaint() {
        super();
    }

    public TextPaint(int flags) {
        super(flags);
    }

    public TextPaint(Paint p) {
        super(p);
    }

    /**
     * Copy the fields from tp into this TextPaint, including the
     * fields inherited from Paint.
     */
    public void set(TextPaint tp) {
        super.set(tp);

        bgColor = tp.bgColor;
        baselineShift = tp.baselineShift;
        linkColor = tp.linkColor;
        drawableState = tp.drawableState;
        density = tp.density;
        underlineColor = tp.underlineColor;
        underlineThickness = tp.underlineThickness;
    }

    /**
     * Returns true if all attributes, including the attributes inherited from Paint, are equal.
     *
     * The caller is expected to have checked the trivial cases, like the pointers being equal,
     * the objects having different classes, or the parameter being null.
     * @hide
     */
    public boolean hasEqualAttributes(@NonNull TextPaint other) {
        return bgColor == other.bgColor
                && baselineShift == other.baselineShift
                && linkColor == other.linkColor
                && drawableState == other.drawableState
                && density == other.density
                && underlineColor == other.underlineColor
                && underlineThickness == other.underlineThickness
                && super.hasEqualAttributes((Paint) other);
    }

    /**
     * Defines a custom underline for this Paint.
     * @param color underline solid color
     * @param thickness underline thickness
     * @hide
     */
    public void setUnderlineText(int color, float thickness) {
        underlineColor = color;
        underlineThickness = thickness;
    }

    /**
     * @hide
     */
    @Override
    public float getUnderlineThickness() {
        if (underlineColor != 0) { // Return custom thickness only if underline color is set.
            return underlineThickness;
        } else {
            return super.getUnderlineThickness();
        }
    }
}