linearlayout8.java

android 例子中的确良ApiDemos。很有代表意义

/*
 * Copyright (C) 2007 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.view;

//Need the following import to get access to the app resources, since this
//class is in a sub-package.
import com.example.android.apis.R;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.Gravity;
import android.view.MenuItem;
import android.widget.LinearLayout;


/**
 * Demonstrates horizontal and vertical gravity
 */
public class LinearLayout8 extends Activity {

    private LinearLayout mLinearLayout;

    // Menu item Ids
    public static final int VERTICAL_ID = Menu.FIRST;
    public static final int HORIZONTAL_ID = Menu.FIRST + 1;

    public static final int TOP_ID = Menu.FIRST + 2;
    public static final int MIDDLE_ID = Menu.FIRST + 3;
    public static final int BOTTOM_ID = Menu.FIRST + 4;

    public static final int LEFT_ID = Menu.FIRST + 5;
    public static final int CENTER_ID = Menu.FIRST + 6;
    public static final int RIGHT_ID = Menu.FIRST + 7;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.linear_layout_8);
        mLinearLayout = (LinearLayout)findViewById(R.id.layout);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        super.onCreateOptionsMenu(menu);
        menu.add(0, VERTICAL_ID, 0, R.string.linear_layout_8_vertical);
        menu.add(0, HORIZONTAL_ID, 0, R.string.linear_layout_8_horizontal);
        menu.add(0, TOP_ID, 0, R.string.linear_layout_8_top);
        menu.add(0, MIDDLE_ID, 0, R.string.linear_layout_8_middle);
        menu.add(0, BOTTOM_ID, 0, R.string.linear_layout_8_bottom);
        menu.add(0, LEFT_ID, 0, R.string.linear_layout_8_left);
        menu.add(0, CENTER_ID, 0, R.string.linear_layout_8_center);
        menu.add(0, RIGHT_ID, 0, R.string.linear_layout_8_right);

        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {

        case VERTICAL_ID:
            mLinearLayout.setOrientation(LinearLayout.VERTICAL);
            return true;
        case HORIZONTAL_ID:
            mLinearLayout.setOrientation(LinearLayout.HORIZONTAL);
            return true;

        case TOP_ID:
            mLinearLayout.setVerticalGravity(Gravity.TOP);
            return true;
        case MIDDLE_ID:
            mLinearLayout.setVerticalGravity(Gravity.CENTER_VERTICAL);
            return true;
        case BOTTOM_ID:
            mLinearLayout.setVerticalGravity(Gravity.BOTTOM);
            return true;

        case LEFT_ID:
            mLinearLayout.setHorizontalGravity(Gravity.LEFT);
            return true;
        case CENTER_ID:
            mLinearLayout.setHorizontalGravity(Gravity.CENTER_HORIZONTAL);
            return true;
        case RIGHT_ID:
            mLinearLayout.setHorizontalGravity(Gravity.RIGHT);
            return true;

        }
        return super.onOptionsItemSelected(item);
    }
}