Develop Reference

Overlay over an ImageView on Android

So I have a list of images that come from the web, I don't know which color are they and I want to place a text over the ImageView.
My idea is to place the ImageView, an image overlay with transparency gradient over that ImageView and the text above it. I want to mimic this behaviour:
Is there anyway to do this via XML?

When you write the XML for your list items which get inflated in the getView(...) of whatever ListAdapter you've written you can surely do this.
Something like this for the list item:
<?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">
<ImageView
android:layout_width="320dp"
android:layout_height="240dp"
android:background="#ACACAC"/>
<RelativeLayout
android:layout_width="320dp"
android:layout_height="240dp"
android:background="#drawable/gradient">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Here is your text"
android:textColor="#000000"
android:layout_alignParentBottom="true"/>
</RelativeLayout>
</RelativeLayout>
Then you create that drawable/gradient. For that you can recycle the answer from here.

Thanks to adityajones I managed to get there :)
So although this is my right answer, I'll mark his as the correct one!
<?xml version="1.0" encoding="utf-8"?>
<ImageView
android:layout_width="fill_parent"
android:layout_height="200dp"
android:scaleType="centerCrop"
android:src="#drawable/image" />
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="200dp"
android:background="#drawable/gradient_image" >
<TextView
android:id="#+id/text"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_margin="6dp"
android:layout_marginBottom="18dp"
android:shadowColor="#000"
android:shadowRadius="7.0"
android:text="This is some random text"
android:textColor="#color/white"
android:textSize="22sp" />
</RelativeLayout>

I'd use a FrameLayout or RelativeLayout. The first View you add to either should be the background ImageView, then obviously you'll need some TextViews and Other ImageViews [or Buttons, or ImageButtons, etc]
Seems like a reasonable layout: a background image, and then one additional view in each corner.
For the gradient, you'll probably want a separate Layout/View at the bottom with a gradient drawable as the background, although I can imagine you might be able to get away with setting the background of one of your TextViews as the gradient.

You do not have to use a gradient drawable file or set it in your xml..
you can do this pragmatically using GradientDrawable Class as explained in this related Question (Create a radial gradient programmatically) then set it as a background for a layout that covers your ImageView, this gives you ability to use different colors and orientations

Android Button and drawable area

I am novice on Android programming.
My task is simple: I want to create a screen with just two objects:
an action Button;
a drawable area in wich to draw images, text, circles, and so on.
Is it possible so have a working example, or at least a guideline ?
I know how to subclass a view, and to draw int it, using:
MyView d = new MyView(this);
setContentView(d);
But this fills all the screen with MyView and the button is not visible.
Some suggestions ?

You need to define a layout file and specify relative position of button and the drawable area.
Make sure both of them are not specified as fill_parent in layout_width or layout-height.
Set the contentView to this layout file

You go through android Ui for detail understanding.
When you create an android project in eclipse you'll find res/layout/main.xml and this is where your default UI is defined and that is set using setContentView(R.layout.main); in onCreate method.
To put images you can use imageview and textview for Texts in xml. Like that many widgets are there for edit text, Button etc. A simple example including Imageview,textview and Button:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<ImageView
android:id="#+id/imageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/ic_launcher" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="HELLO ANDROID"
android:layout_gravity="center"
/>
<Button
android:layout_height="wrap_content"
android:layout_width="fill_parent"
android:text="Click Me"
/>

Android Image Button Layout

Could someone please explain how android uses image button sizes? I seem to be getting odd behavior with my buttons.
I have the following code as an example. I have two buttons that sit at the bottom of my layout. These buttons share 50% of the total width as they sit side-by-side.
Within Abode PS, the two images (used for these two buttons) are actually 2" x 38" or 495x94 pixels. This size is of course larger than the available space in the layout.
I am using edge effects on my buttons to give them definition. Android is cutting the edges off my buttons in order to center then in the available layout space.
This particular layout that I am working on will only allow vertical orientation, in case that helps.
Thank you.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/scrollView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<LinearLayout
android:id="#+id/layout"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true" >
<ImageButton
android:id="#+id/ImageButton1"
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_marginLeft="1dip"
android:layout_marginRight="1dip"
android:layout_weight="1"
android:background="#FF000000"
android:src="#drawable/map4" >
</ImageButton>
<ImageButton
android:id="#+id/ImageButton3"
android:layout_width="0dip"
android:layout_marginRight="1dip"
android:layout_weight="1"
android:background="#FF000000"
android:src="#drawable/buy"
android:layout_height="wrap_content"
android:layout_marginLeft="1dip">
</ImageButton>
</LinearLayout>
</RelativeLayout>

Try using an ImageView and android:scaleType:
http://developer.android.com/reference/android/widget/ImageView.html#attr_android:scaleType
Experiment the values available to see what is the best combination!
Then add a listener to behave like a button...

try use the button and make it with empty text after this set the background .
or :
use the image button and put the source and the background the same image to get button exactly like the image
**you can use the selector to make some beauty for application buttons
Google it it's easy to use ;)

How to get UI to look right

I am having a problem getting the ListView to display properly. It currently looks like this with the following xml code:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#drawable/favs_main">
<Button
android:text="Return to Home"
android:id="#+id/return_button"
android:layout_width="150dp"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:layout_centerHorizontal="true"
android:layout_alignParentBottom="true"
android:textSize="15sp"/>
<ListView
android:id="#+id/favsListView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="180dp"
android:layout_above="#id/return_button"/>
</RelativeLayout>
If you notice the list is down on the screen. I want it to be just below the favorites text instead of just above the return to home button. The catch however is that I always want the button to show and the list view to just occupy the space between the favorites text and the button. The text is from the background image so I can't just align below that. So even with 100 items I would still like to show the button.
Thanks for the help

If the word "favorites" is part of a background image as suggested in the RelativeLayout's background attribute, then you won't be able to align an element below it without using hacky margins or something to that effect. If you want to align an element below the word, separate that into a different ImageView and set the layout_below of the ListView to the id of that ImageView. To get an element to align properly in between two other elements, use a combination of layout_above and layout_below.

Couldn't you just align the ListView to the Parents' Top and set a margin for the ListView so that it is below the Text of the Background?
Also you could change the background to provide the Text in an ImageView and align the ListView to be below the ImageView.

Instead of trying to make a persistent View always show up under the ListView and align it (which you can do, see other suggestions), you might want to take a look at using a footerView:
http://developer.android.com/intl/de/reference/android/widget/ListView.html#addFooterView
"Add a fixed view to appear at the bottom of the list."
Note that it can be another layout too if you eventually need to do more than just one Button.

this my listview which have multiple entries and textview and button fixed in the botton. i haven't inserted background. try this hope it will help.
http://www.techuv.com/layout-with-butoon-and-textview-fixed-in-bottom/

You could use a simple LinearLayout and use the weight attribute on the ListView :
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:background="#drawable/favs_main">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
<ListView
android:id="#+id/favsListView"
android:layout_width="wrap_content"
android:layout_weight="1"
android:layout_height="wrap_content"
android:layout_marginTop="180dp"/>
<Button
android:text="Return to Home"
android:id="#+id/return_button"
android:layout_width="150dp"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:layout_centerHorizontal="true"
android:textSize="15sp"/>
</LinearLayout>

android layout question

Currently I'm working on a dialog which consists of title, description, tags and footer. The title can be long and in this case the text should automatically be displayed in multiple lines. The description is also longer and should fill multiple lines.
At the bottom of the dialog has to be the footer (also if the title and description don't fill whole screen).
I tried to do create the layout described about but had a problem with long text - if the content is long it doesn't display multiple lines but extends main view (LinearView) so the content extends over the visible area.
Here I'm pasting the print screen of the current state and the mockup of the desired layout:
alt text http://img52.imageshack.us/img52/9697/androidscreenshot.png
alt text http://img69.imageshack.us/img69/3609/screenshot20091227at716.png
TextView "Footer" and buttons OK and Cancel should appear at the bottom of the screen and the title ("Title Title Title...) and description text should automatically appear in multiple lines instead of extending the parent view.
I would really appreciate if anyone of you could give a tip about solving these layout issues.
Thanks!

Something like this should help: placing the text elements up top, and forcing the buttons to the bottom of the layout using weightSum. I can't remember the settings for multi-line text offhand, but if you're not using the singleLine attribute set to true, then things should work out ok.
Check the XML attribute documentation for more info.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:weightSum="1">
<TextView
android:id="#id/android:title"
android:layout_width="fill_parent"
android:layout_weight="1" />
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:weightSum="2">
<Button
android:id="#+id/btn_ok"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="#string/btn_ok" />
<Button
android:id="#+id/btn_cancel"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="#string/btn_cancel" />
</LinearLayout>
</LinearLayout>