Java tutorial
/* * Copyright (C) 2011 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.widget; import android.content.Context; import android.graphics.Canvas; import android.util.AttributeSet; import android.view.View; /** * Space is a lightweight View subclass that may be used to create gaps between components * in general purpose layouts. */ public final class Space extends View { /** * {@inheritDoc} */ public Space(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) { super(context, attrs, defStyleAttr, defStyleRes); if (getVisibility() == VISIBLE) { setVisibility(INVISIBLE); } } /** * {@inheritDoc} */ public Space(Context context, AttributeSet attrs, int defStyleAttr) { this(context, attrs, defStyleAttr, 0); } /** * {@inheritDoc} */ public Space(Context context, AttributeSet attrs) { this(context, attrs, 0); } /** * {@inheritDoc} */ public Space(Context context) { //noinspection NullableProblems this(context, null); } /** * Draw nothing. * * @param canvas an unused parameter. */ @Override public void draw(Canvas canvas) { } /** * Compare to: {@link View#getDefaultSize(int, int)} * If mode is AT_MOST, return the child size instead of the parent size * (unless it is too big). */ private static int getDefaultSize2(int size, int measureSpec) { int result = size; int specMode = MeasureSpec.getMode(measureSpec); int specSize = MeasureSpec.getSize(measureSpec); switch (specMode) { case MeasureSpec.UNSPECIFIED: result = size; break; case MeasureSpec.AT_MOST: result = Math.min(size, specSize); break; case MeasureSpec.EXACTLY: result = specSize; break; } return result; } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { setMeasuredDimension(getDefaultSize2(getSuggestedMinimumWidth(), widthMeasureSpec), getDefaultSize2(getSuggestedMinimumHeight(), heightMeasureSpec)); } }