X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=blobdiff_plain;f=altosdroid%2Fapp%2Fsrc%2Fmain%2Fjava%2Forg%2Faltusmetrum%2FAltosDroid%2FTabsAdapter.java;fp=altosdroid%2Fapp%2Fsrc%2Fmain%2Fjava%2Forg%2Faltusmetrum%2FAltosDroid%2FTabsAdapter.java;h=b34a25b60c8a3973cd8fc1640be2655df41b2010;hp=0000000000000000000000000000000000000000;hb=8b53f860eb3171cd43e4bd0e440f2889bd810662;hpb=4a257455b2dc57069c41e1845daf66239c5cbe1d

diff --git a/altosdroid/app/src/main/java/org/altusmetrum/AltosDroid/TabsAdapter.java b/altosdroid/app/src/main/java/org/altusmetrum/AltosDroid/TabsAdapter.java
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+/*
+ * 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) {
+	}
+}