Develop Reference

Android design : a scrollview 3 button below

I'm trying to create a design (and i'm pretty bad at this -__- ) where I will have a scrollview and a set of 3 buttons, horizontally aligned ALWAYS at the bottom of the screen (I mean the scrollview should be ABOVE my layout with my button and may scroll, but the button have to ALWAYS be displayed/visible)
I have already tried several solution, the last one I used is this , but it doesn't succeeded :(
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<RelativeLayout
android:id="#+id/header"
android:layout_alignParentTop="true"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</RelativeLayout>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/scroll"
android:layout_above="#+id/footer"
android:layout_below="#+id/header">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/imageView1"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Chargement en cours"
android:id="#+id/TNom"
android:layout_below="#+id/imageView1"
android:layout_centerHorizontal="true" />
</RelativeLayout>
</ScrollView>
<RelativeLayout
android:id="#+id/footer"
android:layout_width="match_parent"
android:layout_height="wrap_content">
android:layout_alignParentBottom="true">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="+"
android:id="#+id/Bplus"
android:onClick="onClickSuivant"
android:layout_toLeftOf="#+id/Begale"
android:layout_toStartOf="#+id/Begale" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="="
android:id="#+id/Begale"
android:onClick="onClickSuivant"
android:layout_centerHorizontal="true" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="-"
android:id="#+id/Bmoins"
android:onClick="onClickSuivant"
android:layout_toRightOf="#+id/Begale"
android:layout_toEndOf="#+id/Begale" />
</RelativeLayout>
NB : I have no need of the "header" part ... but the last code I found have it and it seems to be exactly I need.... seemed only -__- :(
And I have 2 questions on this design (while i'm asking, I ask everything :p )
1/ How may I force the size of the Image I will be downloading into ImageView1 to a "maximum" height (I mean my picture will be portrait OR landscape... let say 10*15 and 15*10 ... how may i forced them to be 10*6.666 instead of 15*10 <= It's an example... I don't know the image size I will have, but I know I want them at the same height every time, width may change according to the ratio)
2/why Lint is writing this part in red....
android:textAppearance="?android:attr/textAppearanceLarge"
Thx in advance to everyone who stops here and give me hints :)
(and sorry for my english)
EDIT : I have found some answer !! I used RELATIVELayout instead of LINEARLayout, which is recommended to do what I wanted ...
Si here is the "new" template (for reference if anyone is interested), where I still have problem
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
android:orientation="vertical">
<ScrollView
android:layout_width="match_parent"
android:id="#+id/scroll"
android:layout_height="0dp"
android:layout_weight="1">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<ImageView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/imageView1"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Chargement en cours"
android:id="#+id/TNom"
android:layout_below="#+id/imageView1"
android:layout_centerHorizontal="true" />
</LinearLayout>
</ScrollView>
<LinearLayout
android:id="#+id/footer"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:orientation="horizontal">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="+"
android:id="#+id/Bplus"
android:onClick="onClickSuivant"
android:layout_toLeftOf="#+id/Begale"
android:layout_toStartOf="#+id/Begale" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="="
android:id="#+id/Begale"
android:onClick="onClickSuivant"
android:layout_centerHorizontal="true" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="-"
android:id="#+id/Bmoins"
android:onClick="onClickSuivant"
android:layout_toRightOf="#+id/Begale"
android:layout_toEndOf="#+id/Begale" />
</LinearLayout>
With the previous design, button were well aligned and take all the screen (match_parent) ... with this one, they are located at the bottom left ... As android:layout_centerHorizontal="true" is made for RelativeLayout, problem come from this... how may i change it ?

Try using android:gravity="center" in your LinearLayout (which encapsulates the buttons) or android:layout_gravity="center" in Button elements. I believe the first option will be enough.
EDIT: regarding Lint warning message, I believe it's related to this line:
android:text="Chargement en cours"
It's discouraged to use hard-coded strings. Try replacing it by android:text="#string/my_string_id" and define such string in your strings.xml file.

Trying to draw an arbitrary background image

I've already seen many tutorials trying to put an image as background of my main activity. Tested many ways, and now I'm with this:
<?xml version="1.0" encoding="utf-8"?>
<merge
xmlns:android="http://schemas.android.com/apk/res/android">
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/imageView"
android:src="#drawable/library"
android:scaleType = "centerCrop"
android:contentDescription="#string/bckgrndimg" />
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#ffffff"
android:orientation="vertical"
>
<ListView
android:id="#android:id/list"
android:layout_width="match_parent"
android:layout_height="370dp"
android:layout_marginLeft="0dp"
android:layout_alignParentBottom="true"
android:layout_alignParentStart="true">
</ListView>
<Button
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/nuevo_libro"
android:id="#+id/nuevoLibro"
android:layout_above="#android:id/list"
android:layout_centerHorizontal="true"
android:layout_marginBottom="42dp" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="#string/biblioteca_virtual"
android:id="#+id/textView2"
android:layout_above="#+id/nuevoLibro"
android:layout_centerHorizontal="true"
android:layout_marginBottom="31dp" />
</RelativeLayout>
</merge>
Ok, this should go ok, shouldn't it? My "library" image is a 900x600 PNG image, but it just doesn't show up on the screen.
Am I missing something?
Thank you!

Do you need an Image View?
You could do something like this:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#drawable/library.."
...
>
...
</RelativeLayout>

Change Background color of RelativeLayout
android:background="#ffffff"
To
android:background="#android:color/transparent"

Android layout objects placement

I have this simple activity in my android app but I don't know how to place my button so it appears at the same position on various screen sizes.
I want the button to always be placed at the bottom of the screen. The screenshot shown is from a phone screen. When displayed on a larger screen the button is higher up.
How can I fix this?
Thanks
See this screenshot

You can use RelativeLayout with this parameter (android:layout_alignParentBottom="true")
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:text="Click Me!"/>
</RelativeLayout>

You should use a RelativeLayout
If you have a RelativeLayout that fills the whole screen you should be able to use android:layout_alignParentBottom to move the button to the bottom of the screen.
If your button at the bottom doesn't show then probably the layout above it takes all the space. In this case you can put the button first in your layout file and position the rest of the layout above the views with android:layout_above.

Have a look a RelativeLayout. Use this ViewGroup and add a Button inside it with alignParentBottom
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
<Button
android:id="#+id/button_id"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:alignParentBottom="true"
android:text="HORAIRE"
android:layout_margins="<your_margin_in_dp>" />
</RelativeLayout>

Make footerButton.xml:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/footer"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:gravity="center" >
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="5dp"
android:text="HORAIRE"
android:textColor="#ffffff"
android:textSize="20sp" />
</RelativeLayout>
And add it in all your layout file like below line:
Android Activity_Layout
<RelativeLayout
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" >
<!-- Footer aligned to bottom -->
<include layout="#layout/footer" />
<!-- Content above footer -->
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_above="#id/footer"
android:layout_below="#id/header"
android:gravity="center">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Content goes here"
android:textColor="#FFFFFF"
android:textSize="20sp" />
</RelativeLayout>
</RelativeLayout>
Hope it will solve your problem

This is what I ended up doing. Thanks to everyone who posted, it helped me get in the right direction!
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/container"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
tools:showIn="#layout/activity_main"
tools:context="xxxx.MainActivity"
android:orientation="vertical"
android:weightSum="1">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Dernières nouvelles Twitter"
android:id="#+id/textView"
android:textStyle="bold"
android:textSize="17dp"
android:paddingLeft="8dp"
android:paddingTop="6dp"
android:paddingRight="6dp"
android:paddingBottom="6dp"
android:layout_alignParentTop="true"/>
<ListView
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:id="#+id/listView_tweets"
android:layout_above="#+id/buttonDisplay"
android:choiceMode="none"
android:paddingTop="25dp"
android:paddingLeft="10dp"
android:paddingRight="10dp"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Horaire"
android:layout_margin="5dp"
android:id="#+id/buttonDisplay"
android:onClick="buttonGotoDisplay"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"/>
</RelativeLayout>

layout_weight changes when I add a view into the layout (Android)

I am creating a design in Android for this list item:
I thought that the best solution would be create a linear layout with two relative layout inside it and a space. So I have tried to do it but I have a problem with weights.
In this picture you can see that I have added two relative layout with a space using layout_weight of linear_layout and the proportion works.
This is the code:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#drawable/fondo_chiste_lista_item"
android:weightSum="147"
android:orientation="vertical" >
<RelativeLayout
android:layout_width="match_parent"
android:layout_weight="41"
android:layout_height="0dp" >
</RelativeLayout>
<RelativeLayout
android:layout_width="match_parent"
android:layout_weight="94"
android:layout_height="0dp" >
</RelativeLayout>
<android.support.v7.widget.Space
android:id="#+id/space1"
android:layout_width="wrap_content"
android:layout_weight="12"
android:layout_height="0dp" />
</LinearLayout>
But, now If I add a textview inside a relative layout proportions won't work. As you can see the boxes of the relative layouts have a different size.
This is the code:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#drawable/fondo_chiste_lista_item"
android:weightSum="147"
android:orientation="vertical" >
<RelativeLayout
android:layout_width="match_parent"
android:layout_weight="41"
android:layout_height="0dp" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="46dp"
android:text="TextView" />
</RelativeLayout>
<RelativeLayout
android:layout_width="match_parent"
android:layout_weight="94"
android:layout_height="0dp" >
</RelativeLayout>
<android.support.v7.widget.Space
android:id="#+id/space1"
android:layout_width="wrap_content"
android:layout_weight="12"
android:layout_height="0dp" />
</LinearLayout>
So... What is the problem? Why the proportion change when I add elements? Is there any better solution?

I will add is as an answer since that fixed your problem
instead of
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
use something like
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"

Can not get ImageView to display

My intent is to create a list of widgets on a scroll view, with an ImageView in the centre of the screen behind them. Here is what I have, there will be more buttons when all is said and done:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<ImageView xmlns:android="http://schemas.android.com/apk/res/android"
android:contentDescription="#string/description"
android:src="#drawable/myImage"
android:id="#+id/imageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:scaleType="centerInside" />
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:background="#android:color/transparent">
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:orientation="vertical"
android:background="#android:color/transparent">
<Button xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/newButton"
style="#style/homeScreenButton"
android:text="#string/new_profile" />
<Button xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/loadButton"
style="#style/homeScreenButton"
android:text="#string/load_profile" />
<Button xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/calculatorButton"
style="#style/homeScreenButton"
android:text="#string/calculator" />
</LinearLayout>
</ScrollView>
</RelativeLayout>
On eclipse's xml graphical layout interpreter, the screen is shown as expected. The same is true with the 2 different emulators that I tried, Android 2.2 and Android 4.0.3. But when I send to my actual device, Droid 4 w/Android 4.1.2 the image simply does not show up. I even tried making the ScrollView transparent (android:alpha="0") thinking that it was somehow covering the image up, but nothing. Any suggestions would be greatly appreciated.

try eliminating this line from ImageView,
xmlns:android="http://schemas.android.com/apk/res/android"
it should be present only in the RelativeLayout
so your xml file become
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<ImageView
android:contentDescription="#string/description"
android:src="#drawable/myImage"
android:id="#+id/imageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:scaleType="centerInside" />
<ScrollView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:background="#android:color/transparent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:orientation="vertical"
android:background="#android:color/transparent">
<Button
android:id="#+id/newButton"
style="#style/homeScreenButton"
android:text="#string/new_profile" />
<Button
android:id="#+id/loadButton"
style="#style/homeScreenButton"
android:text="#string/load_profile" />
<Button
android:id="#+id/calculatorButton"
style="#style/homeScreenButton"
android:text="#string/calculator" />
</LinearLayout>
</ScrollView>
</RelativeLayout>

I figured it out, the code was fine. My problem was that the image was in /res/drawable but it needed to be in /res/drawable-hdpi.