Java tutorial
/* * Copyright (C) 2010 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.preference; import android.content.Context; import android.content.res.TypedArray; import android.util.AttributeSet; import android.view.View; import android.widget.FrameLayout; /** * @hide */ public class PreferenceFrameLayout extends FrameLayout { private static final int DEFAULT_BORDER_TOP = 0; private static final int DEFAULT_BORDER_BOTTOM = 0; private static final int DEFAULT_BORDER_LEFT = 0; private static final int DEFAULT_BORDER_RIGHT = 0; private final int mBorderTop; private final int mBorderBottom; private final int mBorderLeft; private final int mBorderRight; private boolean mPaddingApplied; public PreferenceFrameLayout(Context context) { this(context, null); } public PreferenceFrameLayout(Context context, AttributeSet attrs) { this(context, attrs, com.android.internal.R.attr.preferenceFrameLayoutStyle); } public PreferenceFrameLayout(Context context, AttributeSet attrs, int defStyleAttr) { this(context, attrs, defStyleAttr, 0); } public PreferenceFrameLayout(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) { super(context, attrs, defStyleAttr, defStyleRes); final TypedArray a = context.obtainStyledAttributes(attrs, com.android.internal.R.styleable.PreferenceFrameLayout, defStyleAttr, defStyleRes); float density = context.getResources().getDisplayMetrics().density; int defaultBorderTop = (int) (density * DEFAULT_BORDER_TOP + 0.5f); int defaultBottomPadding = (int) (density * DEFAULT_BORDER_BOTTOM + 0.5f); int defaultLeftPadding = (int) (density * DEFAULT_BORDER_LEFT + 0.5f); int defaultRightPadding = (int) (density * DEFAULT_BORDER_RIGHT + 0.5f); mBorderTop = a.getDimensionPixelSize(com.android.internal.R.styleable.PreferenceFrameLayout_borderTop, defaultBorderTop); mBorderBottom = a.getDimensionPixelSize(com.android.internal.R.styleable.PreferenceFrameLayout_borderBottom, defaultBottomPadding); mBorderLeft = a.getDimensionPixelSize(com.android.internal.R.styleable.PreferenceFrameLayout_borderLeft, defaultLeftPadding); mBorderRight = a.getDimensionPixelSize(com.android.internal.R.styleable.PreferenceFrameLayout_borderRight, defaultRightPadding); a.recycle(); } /** * {@inheritDoc} */ @Override public LayoutParams generateLayoutParams(AttributeSet attrs) { return new LayoutParams(getContext(), attrs); } @Override public void addView(View child) { int borderTop = getPaddingTop(); int borderBottom = getPaddingBottom(); int borderLeft = getPaddingLeft(); int borderRight = getPaddingRight(); android.view.ViewGroup.LayoutParams params = child.getLayoutParams(); LayoutParams layoutParams = params instanceof PreferenceFrameLayout.LayoutParams ? (PreferenceFrameLayout.LayoutParams) child.getLayoutParams() : null; // Check on the id of the child before adding it. if (layoutParams != null && layoutParams.removeBorders) { if (mPaddingApplied) { borderTop -= mBorderTop; borderBottom -= mBorderBottom; borderLeft -= mBorderLeft; borderRight -= mBorderRight; mPaddingApplied = false; } } else { // Add the padding to the view group after determining if the // padding already exists. if (!mPaddingApplied) { borderTop += mBorderTop; borderBottom += mBorderBottom; borderLeft += mBorderLeft; borderRight += mBorderRight; mPaddingApplied = true; } } int previousTop = getPaddingTop(); int previousBottom = getPaddingBottom(); int previousLeft = getPaddingLeft(); int previousRight = getPaddingRight(); if (previousTop != borderTop || previousBottom != borderBottom || previousLeft != borderLeft || previousRight != borderRight) { setPadding(borderLeft, borderTop, borderRight, borderBottom); } super.addView(child); } public static class LayoutParams extends FrameLayout.LayoutParams { public boolean removeBorders = false; /** * {@inheritDoc} */ public LayoutParams(Context c, AttributeSet attrs) { super(c, attrs); TypedArray a = c.obtainStyledAttributes(attrs, com.android.internal.R.styleable.PreferenceFrameLayout_Layout); removeBorders = a.getBoolean( com.android.internal.R.styleable.PreferenceFrameLayout_Layout_layout_removeBorders, false); a.recycle(); } /** * {@inheritDoc} */ public LayoutParams(int width, int height) { super(width, height); } } }