Develop Reference

Android fragment preloading data

Hello I'm trying to make an application that has multiple bottomnaviagtion tabs.
Currently it works because fragment data (for example, images) are static. However, if I want to make them dynamic, I'll have to create a preloader.
So I want to display a loading layout (for example R.layout.loading) UNTIL (async) function has completed and obtained data from server. Then I want to replace the layout in the fragment with a new layout (R.layout.datafragment)
Fragment onCreateView:
return inflater.inflate(R.layout.loading, container, false);
In summary it should work exactly like youtube bottom tabs.

You should create in your activity layout a placeholder for those dynamic fragments and a loader which is by default gone, but when you start loading data from the server you should make it visible (loader). Then, when you load necessary data, just start fragment transition and place whatever fragment you have loaded.

Your parent activity's layout should be like this:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<!--Navigation View and Fragment Container-->
</RelativeLayout>
<RelativeLayout
android:id="#+id/progress_layout
android:layout_width="match_parent"
android:layout_height="match_parent">
<ProgressBar
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"/>
</RelativeLayout>
</RelativeLayout>
Then you simply show/hide progressLayout based on your requirement. Thanks

Easiest way to re-use layout in multiple activities

I'm trying to use a NavBar (http://imgur.com/a/fygH3) at the bottom of each page/activity. when an image is clicked, it opens a new page. Such as a page containing a countdown timer.
Would the best way to do this be load the navbar layout onto the bottom of a page containing a countdown timer.Or is it possible to just use one navbar layout page that has a mainActivity layout, then load a countdownPage into the main activity layout, upon a button press?
This would be done for 5 different activities/pages.

You could create a bottom layout, then add it on your layout's activities.
Generic Layout my_bottom_layout.xml
<RelativeLayout android:id="#+id/bottom_layout">
<RecyclerView/>
</RelativeLayout>
Layout's Activities
<RelativeLayout
android:id="#+id/layout_1">
...
<include layout="#layout/my_bottom_layout" />
</RelativeLayout>
<RelativeLayout
android:id="#+id/layout_2">
...
<include layout="#layout/my_bottom_layout" />
</RelativeLayout>

going to another xml from the main xml

I m totally new to program and I m trying to make a simple app.
I need to jump from one xml to another xml by clicking a button, and I m stopped here.
I only know how to use graphical layout and how should I do it???
I want to jump from Activity_Main.xml to 2bb.xml, and 2bb.xml to 2result.xml and at last from 2result.xml back to Activity_Main.xml.
my A_M.xml
<GridLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:columnCount="1"
tools:context="com.example.soo.MainActivity"
tools:ignore="MergeRootFrame,NewApi,UnusedAttribute" >
<Button
android:id="#+id/button1"
android:layout_width="150dp"
android:layout_height="215dp"
android:layout_column="0"
android:layout_gravity="left|top"
android:layout_row="0"
android:text="#string/B2"
android:onClick="2bb" />

There are a few ways to achieve this, depends on what your looking for.
You can call a new activity from your MainActivity and inflate 2bb.xml when the new activity is created, or you can use different fragments, and just transition between fragments in the same activity. I suggest going over some tutorials regarding Activities and Fragments in Android.

Try this
To go to other xml, you have to create one activity for one xml and each button has to put action startactivity.

Android: Default layout for listitem containing title and subtitle

I have made a listitem, containing a title and a subtitle. Looking to the result, I think it doesn't look really professional. So that's why I'm asking.
The listitem I'm looking for is pretty common (it's used in a lot of apps i.e. Android's default settings menu and it's also shown when you add a listview in the graphical layout editor tab in eclipse).
So my question is: Where can I find a default layout for a listitem with a title and a subtitle?

Resource id is android.R.layout.simple_list_item_2
Upper text line has id android.R.id.text1 and lower one - android.R.id.text2
Layout is located in the <ANDROID_SDK_ROOT>/platforms/<any_api_level>/data/res/layout folder
OR
You can use TwoLineListItem from the default Android controls list(it is located under "Advanced" tab in Eclipse Layout Editor)
OR
You can build your own layout with anything you like(for example LinearLayout with orientation="vertical" and two TextEdits added

So The Best Way Is:- I took out the simple list item 2 and made an layout in my project and with little editing it took the same layout as you may give in android.R.simple_list_item_2
So the code is:-
<?xml version="1.0" encoding="utf-8"?>
<TwoLineListItem xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:minHeight="?attr/listPreferredItemHeight"
android:mode="twoLine"
android:paddingStart="?attr/listPreferredItemPaddingLeft"
android:paddingLeft="?attr/listPreferredItemPaddingLeft"
android:paddingEnd="?attr/listPreferredItemPaddingRight"
android:paddingRight="?attr/listPreferredItemPaddingRight">
<TextView android:id="#+id/text1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="8dp"
android:textAppearance="?attr/textAppearanceListItem" />
<TextView android:id="#id/text2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#id/text1"
android:layout_alignStart="#+id/text1"
android:layout_alignLeft="#+id/text1"
android:textAppearance="?attr/textAppearanceListItemSmall" />

android:animateLayoutChanges won't work in parent layout

Suppose I have a layout file structured like this:
<LinearLayout android:id="#+id/main" android:orientation="vertical" android:animateLayoutChanges="true">
<EditText>
<TextView android:id="#+id/header1">
<LinearLayout android:id="#+id/insertionPoint" android:orientation="vertical" android:animateLayoutChanges="true">
</LinearLayout>
<TextView android:id="#+id/header2">
</LinearLayout>
I want to dynamically add text fields to the Layout insertionPoint and I would like to see an animation of the elements below it (in this case, header2) sliding down.
Using android:animateLayoutChanges only animates the elements in the layout insertionPoint, so there is no animation for header2. What should I do?
Just to be more clear: what I would like to do here is something like the animations that we can see in the People app in ICS when we add more fields, like telephone numbers, to a contact.
Thank you!

API 16 added the LayoutTransition.CHANGING animation type, however it is disabled by default.
To enable:
LinearLayout linearLayout = (LinearLayout) findViewById(R.id.main);
linearLayout.getLayoutTransition().enableTransitionType(LayoutTransition.CHANGING);
Nice DevBytes video: https://www.youtube.com/watch?v=55wLsaWpQ4g