--- /dev/null
+/*
+ * Copyright (C) 2009 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 org.altusmetrum.AltosDroid;
+
+import java.util.ArrayList;
+
+import android.content.Context;
+import android.os.Bundle;
+import android.support.v4.app.Fragment;
+import android.support.v4.app.FragmentTransaction;
+import android.support.v4.app.FragmentActivity;
+import android.support.v4.app.FragmentPagerAdapter;
+import android.support.v4.view.ViewPager;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.TabHost;
+import android.widget.TabWidget;
+
+/**
+ * This is a helper class that implements the management of tabs and all
+ * details of connecting a ViewPager with associated TabHost. It relies on a
+ * trick. Normally a tab host has a simple API for supplying a View or
+ * Intent that each tab will show. This is not sufficient for switching
+ * between pages. So instead we make the content part of the tab host
+ * 0dp high (it is not shown) and the TabsAdapter supplies its own dummy
+ * view to show as the tab content. It listens to changes in tabs, and takes
+ * care of switch to the correct paged in the ViewPager whenever the selected
+ * tab changes.
+ */
+public class TabsAdapter extends FragmentPagerAdapter
+ implements TabHost.OnTabChangeListener, ViewPager.OnPageChangeListener {
+ private final Context mContext;
+ private final TabHost mTabHost;
+ private final ViewPager mViewPager;
+ private final ArrayList<TabInfo> mTabs = new ArrayList<TabInfo>();
+ private int position;
+
+ static class TabInfo {
+ private final String tag;
+ private final Class<?> clss;
+ private final Bundle args;
+ private Fragment fragment;
+
+ TabInfo(String _tag, Class<?> _class, Bundle _args) {
+ tag = _tag;
+ clss = _class;
+ args = _args;
+ }
+ }
+
+ static class DummyTabFactory implements TabHost.TabContentFactory {
+ private final Context mContext;
+
+ public DummyTabFactory(Context context) {
+ mContext = context;
+ }
+
+ public View createTabContent(String tag) {
+ View v = new View(mContext);
+ v.setMinimumWidth(0);
+ v.setMinimumHeight(0);
+ return v;
+ }
+ }
+
+ public TabsAdapter(FragmentActivity activity, TabHost tabHost, ViewPager pager) {
+ super(activity.getSupportFragmentManager());
+ mContext = activity;
+ mTabHost = tabHost;
+ mViewPager = pager;
+ mTabHost.setOnTabChangedListener(this);
+ mViewPager.setAdapter(this);
+ mViewPager.setOnPageChangeListener(this);
+ }
+
+ public void addTab(TabHost.TabSpec tabSpec, Class<?> clss, Bundle args) {
+ tabSpec.setContent(new DummyTabFactory(mContext));
+ String tag = tabSpec.getTag();
+
+ TabInfo info = new TabInfo(tag, clss, args);
+ mTabs.add(info);
+ mTabHost.addTab(tabSpec);
+ notifyDataSetChanged();
+ }
+
+ @Override
+ public int getCount() {
+ return mTabs.size();
+ }
+
+ @Override
+ public Fragment getItem(int position) {
+ TabInfo info = mTabs.get(position);
+ AltosDebug.debug("TabsAdapter.getItem(%d)", position);
+ info.fragment = Fragment.instantiate(mContext, info.clss.getName(), info.args);
+ return info.fragment;
+ }
+
+ public Fragment currentItem() {
+ TabInfo info = mTabs.get(position);
+ return info.fragment;
+ }
+
+ public void onTabChanged(String tabId) {
+ AltosDroidTab prev_frag = (AltosDroidTab) mTabs.get(position).fragment;
+
+ position = mTabHost.getCurrentTab();
+
+ AltosDroidTab cur_frag = (AltosDroidTab) mTabs.get(position).fragment;
+
+ if (prev_frag != cur_frag) {
+ if (prev_frag != null) {
+ prev_frag.set_visible(false);
+ }
+ }
+ if (cur_frag != null) {
+ cur_frag.set_visible(true);
+ }
+ AltosDebug.debug("TabsAdapter.onTabChanged(%s) = %d", tabId, position);
+ mViewPager.setCurrentItem(position);
+ }
+
+ public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
+ }
+
+ public void onPageSelected(int position) {
+ // Unfortunately when TabHost changes the current tab, it kindly
+ // also takes care of putting focus on it when not in touch mode.
+ // The jerk.
+ // This hack tries to prevent this from pulling focus out of our
+ // ViewPager.
+ TabWidget widget = mTabHost.getTabWidget();
+ int oldFocusability = widget.getDescendantFocusability();
+ widget.setDescendantFocusability(ViewGroup.FOCUS_BLOCK_DESCENDANTS);
+ mTabHost.setCurrentTab(position);
+ widget.setDescendantFocusability(oldFocusability);
+ }
+
+ public void onPageScrollStateChanged(int state) {
+ }
+}
projects / fw / altos / blobdiff