Android example source code file (NumericSprite.java)

This example Android source code file (NumericSprite.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

android, drawing, graphics, labelmaker, numericsprite, paint, string, ui

The NumericSprite.java Android example source code

/*
 * Copyright (C) 2008 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.example.android.apis.graphics.spritetext;

import javax.microedition.khronos.opengles.GL10;

import android.graphics.Paint;

public class NumericSprite {
    public NumericSprite() {
        mText = "";
        mLabelMaker = null;
    }

    public void initialize(GL10 gl, Paint paint) {
        int height = roundUpPower2((int) paint.getFontSpacing());
        final float interDigitGaps = 9 * 1.0f;
        int width = roundUpPower2((int) (interDigitGaps + paint.measureText(sStrike)));
        mLabelMaker = new LabelMaker(true, width, height);
        mLabelMaker.initialize(gl);
        mLabelMaker.beginAdding(gl);
        for (int i = 0; i < 10; i++) {
            String digit = sStrike.substring(i, i+1);
            mLabelId[i] = mLabelMaker.add(gl, digit, paint);
            mWidth[i] = (int) Math.ceil(mLabelMaker.getWidth(i));
        }
        mLabelMaker.endAdding(gl);
    }

    public void shutdown(GL10 gl) {
        mLabelMaker.shutdown(gl);
        mLabelMaker = null;
    }

    /**
     * Find the smallest power of two >= the input value.
     * (Doesn't work for negative numbers.)
     */
    private int roundUpPower2(int x) {
        x = x - 1;
        x = x | (x >> 1);
        x = x | (x >> 2);
        x = x | (x >> 4);
        x = x | (x >> 8);
        x = x | (x >>16);
        return x + 1;
    }

    public void setValue(int value) {
        mText = format(value);
    }

    public void draw(GL10 gl, float x, float y,
            float viewWidth, float viewHeight) {
        int length = mText.length();
        mLabelMaker.beginDrawing(gl, viewWidth, viewHeight);
        for(int i = 0; i < length; i++) {
            char c = mText.charAt(i);
            int digit = c - '0';
            mLabelMaker.draw(gl, x, y, mLabelId[digit]);
            x += mWidth[digit];
        }
        mLabelMaker.endDrawing(gl);
    }

    public float width() {
        float width = 0.0f;
        int length = mText.length();
        for(int i = 0; i < length; i++) {
            char c = mText.charAt(i);
            width += mWidth[c - '0'];
        }
        return width;
    }

    private String format(int value) {
        return Integer.toString(value);
    }

    private LabelMaker mLabelMaker;
    private String mText;
    private int[] mWidth = new int[10];
    private int[] mLabelId = new int[10];
    private final static String sStrike = "0123456789";
}