Develop Reference

Layout issue with Android Studio

Recently picking up android development, I have hit a snag in the road. I'm having trouble positioning my layouts. Screenshots are as follows:
I'm trying to input either another layout type/list view in the upper section of the screen, without disrupting the button/text box at the bottom, though.. When extending this layout. I hit the following snag:
The entire contents of the original frame shift when the box of the new layout is extended, I've tried modifying:
android:layout_gravity="top">
and other layout attributes such as weight, margin, height/width.. This always hits the same problem.
My XML for this view is:
<LinearLayout 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:orientation="horizontal" >
<FrameLayout
android:layout_width="wrap_content"
android:layout_height="483dp"
android:layout_weight="1.06"
android:layout_gravity="top">
</FrameLayout>
<EditText android:id="#+id/edit_message"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:hint="#string/edit_message"
android:layout_gravity="bottom" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/button_send"
android:layout_gravity="bottom"
android:onClick="SendMessageButton"
/>
</LinearLayout>
Though, i'm some-what stuck on how to make the correct changes & any response to this question would be greatly appreciated!

At the moment, all your child views live inside a single horizontally-oriented LinearLayout. LinearLayouts always arrange views sequentially, as you are experiencing.
There are a couple different ways to achieve the layout you are looking for. I'm going to suggest one that uses nested LinearLayouts (an outer one to stack things vertically, and then a nested one to arrange the EditText and Button horizontally), but you could also consider using a RelativeLayout for this.
Updated layout:
<LinearLayout
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:orientation="vertical">
<FrameLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<EditText
android:id="#+id/edit_message"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:hint="#string/edit_message" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/button_send"
android:onClick="SendMessageButton" />
</LinearLayout>
</LinearLayout>
Note that a LinearLayout is oriented horizontally by default; I have explicitly included the attribute here to make the structure more clear.

The reason, your button and editText is appearing far from the frame layout and not near the corner is the parent layout orientation is Horizontal.
Change it to Vertical.
Now, if you need your button and editText to be arranged in the same line, it should be mentioned as described in samgak answer.
However, i would like to suggest the following.
Using framelayout might create bad user experience across different screen sizes in android.
If the parent layout in Linear, if the screen size is x and all your components added if the height it takes is x-20, then the theme you set for parent layout would not cover the entire screen. Therefore, it is recommended to use RelativeLayout and for the button and editText, use the layout_alignParentBottom = true attribute.
If needed, i can share the code sample for this. Added Vertical Scroll to the layout.
<ScrollView 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"
>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<FrameLayout
android:layout_width="fill_parent"
android:layout_height="483dp"
android:layout_gravity="top">
</FrameLayout>
<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<EditText android:id="#+id/edit_message"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:hint="Edit Message"
android:layout_gravity="bottom" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Send"
android:layout_gravity="bottom"
android:onClick="SendMessageButton"
/>
</LinearLayout>
</LinearLayout>
</ScrollView>

Android Layout: cannot see the children over the parent

I have the Layouts as you can see in the picture (sorry I cannot post them normally yet):
https://dl.dropboxusercontent.com/u/28640502/Unbenannt.bmp
However, when I execute the app I can only see the camera preview and not the text nor the SeekBar. I know they work, because when I reduce the size of the camera I can see them and interact, but if I want the camera to be like background and then the children over it, it doesn't work.
I have been checking a lot of threads with similar problems but I don't find the solution:
1, 2, 3... Any idea? Thanks a lot!
Here is my xml code just in case:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="0.55"
android:orientation="vertical" >
<FrameLayout
android:id="#+id/camera_preview"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="fill">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<TextView
android:id="#+id/show_height"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="5sp"
android:layout_marginRight="10sp"
android:layout_weight="0.12"
android:text="H" />
<SeekBar
android:id="#+id/select_height"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:layout_margin="5sp"
android:layout_weight="0.91" />
<TextView
android:id="#+id/show_distance"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="0.06"
android:text="Dist" />
</LinearLayout>
</FrameLayout>
</LinearLayout>

try to input both of your layouts in relative layout for example
<LL>
<RL>
<FL>
</FL>
<LL>
</LL>
</RL>
</LL>
this is hapenning because of overlaiyng of LL by FL

You could use the bringToFront() method of the View class.
SeekBar seeker = (SeekBar)findViewById(R.id.select_height);
seeker.bringToFront();
Alernatively you could use the sendToBack() function to put a view behind other views.
Also remember that a view's z-index is determined by the order in which the view is declared in the xml layout file.
I'd also suggest changing the camera preview layout and it's first child layout to be siblings. The one added last in the xml file will be on top.

Switch between button bars

I have a layout xml file:
<?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"
android:orientation="vertical"
android:background="#000000" >
<FrameLayout
android:layout_height="fill_parent"
android:layout_width="fill_parent"
android:layout_above="#+id/taoFooter">
<com.example.gamedice.DrawingPanel
android:id="#+id/taoCanvas"
android:layout_height="fill_parent"
android:layout_width="fill_parent"
android:background="#000000" />
</FrameLayout>
<LinearLayout
android:id="#+id/taoFooter"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:layout_alignParentBottom="true"
style="#android:style/Holo.ButtonBar">
<Button
android:id="#+id/roll1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="#string/roll1"
android:layout_weight="1"
style="#android:style/Widget.Holo.Button.Borderless"
android:onClick="rollTaoDice" />
<Button
android:id="#+id/roll2"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="#string/roll2"
android:layout_weight="1"
style="#android:style/Widget.Holo.Button.Borderless"
android:onClick="rollTaoDice" />
<Button
android:id="#+id/roll3"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="#string/roll3"
android:layout_weight="1"
style="#android:style/Widget.Holo.Button.Borderless"
android:onClick="rollTaoDice" />
<Button
android:id="#+id/roll4"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="#string/roll4"
android:layout_weight="1"
style="#android:style/Widget.Holo.Button.Borderless"
android:onClick="rollTaoDice" />
</LinearLayout>
</RelativeLayout>
In addition to other items in the layout, this layout has a button bar consisting of four buttons at the bottom of the screen. Based on user input, I want to be able to replace this button bar with another predefined set of buttons, and then be able to change back later.
Since I know what the alternate set of buttons will be ahead of time, I thought it might be possible to use an alternate layout xml file, but I couldn't figure out how to do that. Can anyone give me some guidance?

You can add your second set of buttons in a layout like you did with the first, then in the layout xml file set the attribute android:visibility="gone" on the second layout. In your code you can call setVisibility(View.GONE) for one layout (e.g. taoFooter) and setVisibility(View.VISIBLE) on the other layout when you need to switch the buttons out.
Alternatively, if you easily want to add some animations you can add a ViewFlipper around your two alternate button layouts. Only the first one is visible by default. You can switch to the next layout with showNext(). Add calls to setInAnimation() and setOutAnimation() before that to enable the animations.

LinearLayout Problem (2 LLayout in the same XML)

I'm coding new XML fils for desinging an android app and I've some problem by using 2 linearLayour into the same xml...
I've "Error in a XML file: aborting build" with the following code :
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TextView android:id="#+id/texte_firsttab"
android:layout_height="wrap_content"
android:layout_width="wrap_content"/>
</LinearLayout>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<Button android:id="#+id/accessGraphe"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:text="test"
android:onClick="selfDestruct" />
<Button android:id="#+id/accessGraphe2"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:text="test2"
android:onClick="selfDestruct" />
</LinearLayout>
Can we put two linear layout in the same xml file?

Yes you can. But not two at top level.
See this example : http://developer.android.com/resources/tutorials/views/hello-linearlayout.html

You cannot have two top-level layouts. How would the system know how to arrange them? You need to enclose them in another layout that defines this.
I assume that the blanks in front of the <?xml ... tag are due to code formatting in your post and are not present in the actual layout file. That would also cause a problem.

No you cannot.... how would you refer to one or the other from the source code ?
If you want to have two linear layouts at the same time (one on top and one at the bottom), then you need to embed those within another layout :
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weigth="1">
<TextView android:id="#+id/texte_firsttab"
android:layout_height="wrap_content"
android:layout_width="wrap_content"/>
</LinearLayout>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weigth="1" >
<Button android:id="#+id/accessGraphe"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:text="test"
android:onClick="selfDestruct" />
<Button android:id="#+id/accessGraphe2"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:text="test2"
android:onClick="selfDestruct" />
</LinearLayout>
</LinearLayout>

You have two root-level items, which shouldn't happen (this is not specific to Android layout files, you can have only one document element in any XML file).
I wouldn't recommend wrapping the to LinearLayouts in another one, that's too complicated; and it's generally a good idea to avoid nesting layouts, see this article about efficient layouts.
For a TextView and two Buttons, a RelativeLayout would be perfect. It's also more flexible than LLs.

Crashes whenever I try to use a custom view object in XML layout

I have made myself a custom LinearLayout by the name of com.theflyingnerd.DroidMe.DiscreteNumericalRangeSelectorWidget that hosts a couple of spinner widgets. This custom LinearLayout inflates the following XML layout (You might not need to look at this too carefully but it's here for completeness):
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<!-- Min value Spinner -->
<Spinner
android:id="#+id/discrete_numerical_range_selector_min_value_spinner"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="left"
android:layout_weight="1" />
<TextView
android:id="#+id/to_text"
android:text="to"
android:textSize="14sp"
android:paddingLeft="10sp"
android:paddingRight="10sp"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:layout_gravity="center"
android:layout_weight="0">
</TextView>
<!-- Max value Spinner -->
<Spinner
android:id="#+id/discrete_numerical_range_selector_max_value_spinner"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="right"
android:layout_weight="1" />
I have placed one such object in the layout for one of my activities like so:
<?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">
<include layout="#layout/search_form_section_generic_top"/>
<include layout="#layout/search_form_section_car_specific"/>
<com.theflyingnerd.DroidMe.DiscreteNumericalRangeSelectorWidget/>
<include layout="#layout/search_form_section_advanced_options" />
</LinearLayout>
The problem is that my app force closes immediately upon startup. I've checked by putting breakpoints in my custom LinearLayout that none of my custom code is even being run yet. Furthermore, if I copy-paste the layout code for my compound widget in place everything works, which indicates to me that I probably haven't left any important XML attributes out. What could be going wrong?

I fixed it by making the LinearLayout XML element in the widget layout into a merge instead, and moved all of the layout parameters out of the widget XML file and into the activity XML itself, thus replacing
<com.theflyingnerd.DroidMe.DiscreteNumericalRangeSelectorWidget/>
with
<com.theflyingnerd.DroidMe.DiscreteNumericalRangeSelectorWidget
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"/>
If someone could tell me why this worked, it might help me and others doing it again, and you can take credit.

because you must specify the width and height of every view you use in you xml?