Java tutorial
/* * 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.android.inputmethod.latin.setup; import android.content.Context; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.Path; import android.support.v4.view.ViewCompat; import android.util.AttributeSet; import android.view.View; import com.android.inputmethod.latin.R; public final class SetupStepIndicatorView extends View { private final Path mIndicatorPath = new Path(); private final Paint mIndicatorPaint = new Paint(); private float mXRatio; public SetupStepIndicatorView(final Context context, final AttributeSet attrs) { super(context, attrs); mIndicatorPaint.setColor(getResources().getColor(R.color.setup_step_background)); mIndicatorPaint.setStyle(Paint.Style.FILL); } public void setIndicatorPosition(final int stepPos, final int totalStepNum) { final int layoutDirection = ViewCompat.getLayoutDirection(this); // The indicator position is the center of the partition that is equally divided into // the total step number. final float partionWidth = 1.0f / totalStepNum; final float pos = stepPos * partionWidth + partionWidth / 2.0f; mXRatio = (layoutDirection == ViewCompat.LAYOUT_DIRECTION_RTL) ? 1.0f - pos : pos; invalidate(); } @Override protected void onDraw(final Canvas canvas) { super.onDraw(canvas); final int xPos = (int) (getWidth() * mXRatio); final int height = getHeight(); mIndicatorPath.rewind(); mIndicatorPath.moveTo(xPos, 0); mIndicatorPath.lineTo(xPos + height, height); mIndicatorPath.lineTo(xPos - height, height); mIndicatorPath.close(); canvas.drawPath(mIndicatorPath, mIndicatorPaint); } }