Android: Using Object to define View in Layout - android

My post is based on a previous post and greatly simplified.
(Android: Two Views On Top of Each Other Using XML)
The file/object DrawV populates the screen with pink circles and allows one to touch a circle to make it disappear. In another file, private DrawV drawView = new DrawV(this); This populates the screen but does not participate in the layout.
setContentView(drawView) shows the dots,so I know it works. I want to use a layout named setContentView(R.layout.activity_title); which includes two buttons at the top of the screen and dots below. In other words, I was wondering if there is a method to put the dots shown in some sort of View that can be included with buttons in the same layout.
Any help? Please?
Tell me if you need anything.

If DrawV is an Android View (or extends View), you can include it in a regular xml layout file, and then use that layout file with setContentView(int).
To reference the DrawV class in your layout, you'll need to use the fully-qualified name (with the package).
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:id="#+id/buttons"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<Button
android:id="#+id/button_one"
android:text="One"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1.0" />
<Button
android:id="#+id/button_two"
android:text="Two"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1.0" />
</LinearLayout>
<com.example.views.DrawV
android:layout_below="#id/buttons"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</RelativeLayout>
Above, the RelativeLayout is your root view. The LinearLayout, buttons, is a ViewGroup just to hold the two buttons and keep them of equal width (note the layout_width=0dp and equal layout_weight). Your DrawV view will be laid out below the buttons View, and then will match the parent container's width and height (fill it).
If you save this under src/main/res/layout/activity_circles.xml, you'll be able to use setContentView(R.layout.activity_circles) in your Activity to set the layout.

Related

Android Layout proplem

I have a layout contain one image and 3 text field
I've tried to align the image to right and text field to left but I've failed
I've used
android:layout_gravity="right" for image and left to text but it did not work also I've used end and start in gravity with no success
this is the layout code:
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="2dp"
android:layout_marginBottom="2dp"
android:orientation="vertical"
android:background="#drawable/card_background">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<ImageView
android:id="#+id/listthumb"
android:layout_width="80dp"
android:layout_height="50dp"
android:layout_gravity="center_vertical"
android:contentDescription="Rss video thumbnail"
android:src="#drawable/ic_launcher" />
<TextView
android:id="#+id/listtitle"
style="#style/listTitle"
android:maxLines="3"/>
</LinearLayout>
<TextView
android:id="#+id/shortdescription"
android:layout_width="wrap_content"
android:ellipsize="end"
android:maxLines="2"
android:textAppearance="?android:attr/textAppearanceSmall"
android:layout_height="wrap_content"/>
<TextView
android:id="#+id/listpubdate"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="11dp"/>
</LinearLayout>
</FrameLayout>
Try to use a <RelativeLayout> instead of a <LinearLayout>
With the RelativeLayout you could place a widget depending on the position of another widget
Here the Relative Layout description
Hope this will help, I have not had time to test....
One linear layout should have vertical orientation and contain the 3 text fields.
One linear layout should have horizontal orientation and contain both the above linear layout and the image.
To push two views to the edges of the screen, you can also give each a left/right margin and then put a blank view with weight = 1 in between them.
Please read a bit more on how layouts work on Android and the different types available to you. A LinearLayout will stack the containing Views either Horizontally or Vertically one after the other. A FrameLayout is simply a container and the items within have to position themselves. RelativeLayout allow you to position your views with a relative reference to other views (in your case, you can position your ImageView, and then your 3 TextViews relative to where the ImageView is).
If you can use LinearLayout instead of RelativeLayout, you should do so, as RelativeLayout is always slower, due to having to perform two passes prior to rendering as it needs to measure each view and then also perform the layouts based on that. You might be looking for something like (pseudo-code):
<LinearLayout orientation=horizontal>
<LinearLayout orientation=vertical>
<TextView />
<TextView />
<TextView />
</LinearLayout>
<ImageView />
</LinearLayout>
You have not described your question well . Check below code if it works .
You just forgot to add orientation in linear layout containing one text view and a Image view .
Add Orientation to Your Linear Layout.

Design UI Android (Element between CardViews)

My question is more informative. I just want to know how to make such design. I found android application called "weather timeline" and inside of that application between CardViews (as I understand) they used this element which I pointed out in picture below. I think its just ImageView but how to set it as here. It will be interesting to know any idea about that! Thanks for attection!
You could easily do it in the following way.
Let us assume that we are using a collection view where the card element is one type and the black gap with text in the middle is the other.
The cardView would look something like this
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<CardView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="16dp"
android:layout_marginRight="16dp"
android:layout_marginTop="#dimen/circle_radius_half_size"
android:layout_marginBottom="#dimen/circle_radius_half_size">
</CardView>
<ImageView
android:layout_width="#dimen/circle_radius"
android:layout_height="#dimen/circle_radius"
android:layout_align_parentLeft="true"
android:layout_marginLeft="24dp"
android:src="#drawable/circle"
android:rotation="180"/>
<ImageView
android:layout_width="#dimen/circle_radius"
android:layout_height="#dimen/circle_radius"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_marginLeft="24dp"
android:src="#drawable/circle" />
</RelativeLayout>
Where drawable circle looks something like this
and the layout for black grape with text in the middle looks something like this
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="16dp"
android:layout_marginRight="16dp">
<View
android:layout_width="#dimen/width_of_line"
android:layout_height="match_parent"
android:layout_margin_left="#dimen/line_margin"
android:background="#color/white" />
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_margin_left="#dimen/line_margin" >
<!-- The Text View Layouts Here -->
</LinearLayout>
</LinearLayout>
Where line_margin is 24dp + CircleHalfSize - LineWidthHalfSize
Of course the CircleHalfSize and LineWidthHalfSize are in DP
Now it is just a question of arranging them properly via the adapter. Personally I would use the RecyclerView. Great Flexibility.
Also this way if you wanted the bubbles to be gone, all you have to do is set the bubble ImageView's visibility to GONE and that too you can do specifically either for the top or the bottom.
I'm pretty sure that this could be accomplished using 9-patched images.
By determining the way to draw your patches and how to set them as a background for your layouts you'll get the same result.
Quick illustrated demo
By adjusting the two backgrounds exactly one above the other you'll get the UI you posted.
Hope it helps.
Further reading
To see how to draw 9-patched images here is a documentation.
This can be accomplished by using a RelativeLayout. Then you can align all your views however you want inside your main view.
Thus, you would layout Card1 at the top, then layout the bubble connector with your marginTop attribute (remember this is from the top of the container, not from the bottom of the card) to layout that view wherever you want.
Basically, you would use a single RelativeLayout, then align the various views within that container wherever you want in relation to each other (or really in relation to the the top of your main view).
Checkout this Pseudo-code:
<RelativeLayout >
<CardView
layout_height = "8dp"
alignParentTop = "true"
/>
<!-- Connector Image -->
<ImageView
alignParentTop = "true"
layoutMarginTop = "10dp" <!-- or whatever it takes to align properly with CardView -->
/>
</RelativeLayout>

Programmatically added LinearLayouts not equally spaced

I am having some spacing trouble when building part of my UI programmatically in Android 4.0. I am trying to add stylized buttons to a stylized LinearLayout. To space the buttons equally, each one is wrapped in a LinearLayout with a weight of 1. I started with a layout defined in XML (somewhat of a proof of concept,) which renders like I expect:
<LinearLayout android:id="#+id/dialog_footer"
android:layout_width="500dp"
android:layout_height="wrap_content"
android:background="#drawable/dialog_footer">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:orientation="horizontal"
android:gravity="center">
<Button android:id="#+id/cancel"
style="#style/Button"
android:layout_width="130dp"
android:layout_height="38dp"
android:text="Cancel" />
</LinearLayout>
<!-- Another LinearLayout with a nested Button like the one above -->
</LinearLayout>
To add buttons programmatically, I removed the inner LinearLayouts and put them in their own layout file that I can inflate and add to the outer LinearLayout in Java. It is nearly identical.
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:orientation="horizontal"
android:gravity="center" >
<Button android:id="#+id/button"
style="#style/Button"
android:layout_width="130dp"
android:layout_height="38dp" />
</LinearLayout>
And this is roughly how I'm adding buttons in code:
LinearLayout dialogFooter = (LinearLayout)dialogView.findViewById(R.id.dialog_footer);
LinearLayout wrappedButton = (LinearLayout)getLayoutInflater().inflate(R.layout.dialog_button_wrapped, null);
Button button = (Button)wrappedButton.findViewById(R.id.button);
button.setText(R.string.button_one_text);
// button.setOnClickListener(...);
dialogFooter.addView(wrappedButton);
The buttons appear but now they are grouped together and shifted to the left. Is there something Android does when it parses a Layout that I would need to do myself if I'm adding to the dialog_footer? Since weights come into play here, I thought that calling setWeightSum() on the container I'm adding to (dialog_footer) might be necessary but that didn't help. Does anyone have any ideas what might be causing the difference between the XML and Java approaches?
I believe this is your problem:
LinearLayout wrappedButton = (LinearLayout)getLayoutInflater().inflate(R.layout.dialog_button_wrapped, null);
The null should be replaced with the parent view , so that it will get the layoutParams you want to set for it .
Another thing is about the weight you set - you should set the width/height to 0px so that the weight won't cause the layout process work in a weird/inefficient way .
BTW , you can remove the inner layout (that has the button) and use a single button instead. just set the layout_gravity there to center_horizontal .

Android colored view containing textviews

Ive made a program which has a view in the top op the window (right under the title bar).
According to what is goin on in the program, the color of the view will change.
This works just fine.
Now my problem is: I want 2 textviews inside it, next to each other. So probably: View, Tablelayout, tablerow, textview, textview, tablerow end, tablelayout end, view end.
But this does not seem to work. It gave me the error "Java.lang.RuntimeException: Unable to start activity ComponentInfo" and "View can not be cast to viewgroup".
Nowhere in the java code do i touch any of the new views in the xml code, the only java that touches that XML, is TopView = (View)findViewById(R.id.TopView); and TopView.setBackgroundColor(Color.GREEN ); Topview is the outer view, and works perfectly without anything inside it.
This is the XML code
...
<View
android:id="#+id/TopView"
android:layout_width="fill_parent"
android:layout_height="20dp"
android:background="#8E8E8E" >
<TableLayout
android:id="#+id/tableTrolo"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<TableRow
android:id="#+id/TableRow000"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="left"
android:gravity="left"
android:orientation="vertical" >
<TextView
android:id="#+id/lbl1"
android:layout_width="120dp"
android:layout_height="wrap_content"
android:text="Vare :"
android:textSize="22dp" />
<TextView
android:id="#+id/lbl2"
android:layout_width="180dp"
android:layout_height="wrap_content"
android:text="du grim" />
</TableRow>
</TableLayout>
</View>
...
You can not have child-views inside a View.
A View is always the leaf node in a layout hierarchy.
1.Re-write the 1st line of your xml-layout as:
<LinearLayout
android:id="#+id/TopView"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="#8E8E8E">
2.Change corresponding Java code as below:
TopView = (LinearLayout)findViewById(R.id.TopView);
You are placing multiple elements inside a View tag. View's don't hold children Views, there's ViewGroup class for that. Use one of FrameLayout,LinearLayout,RelativeLayout instead.
Don't use View. Change your View to ViewGroup. The difference between View and ViewGroup is that ViewGroup CAN contain other Views. If you want to put some TextViews and other things inside it, you should use ViewGroup or some kind of Layout, like LinearLayout or RelativeLayout.

Difference between Frame and Relative layout?

I'm new to android programming but from how much I have understood of the layouts from the documentation, RelativeLayout is mostly used when you need the views based on some rules and the FrameLayout when you want to overlap views.
But unfortunately for the following program I get the work of FrameLayout done by using RelativeLayout. I got my work done but for understanding, Am I missing something in the difference?
Also, how did the buttons come over my image? (Even the other image is overlapping.)
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<ImageView
android:id="#+id/imageView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#drawable/ic_launcher"
/>
<ImageView
android:id="#+id/imageView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#drawable/ic_launcher"
android:layout_alignParentTop="true"
android:layout_alignLeft="#id/imageView1"
/>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignBottom="#+id/imageView1"
android:gravity="center"
android:orientation="horizontal"
android:weightSum="1.0" >
<Button
android:id="#+id/button1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="0.33"
android:text="Login" />
<Button
android:id="#+id/button2"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="0.33"
android:text="Register" />
<Button
android:id="#+id/button3"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="0.33"
android:text="Try application" />
</LinearLayout>
</RelativeLayout>
The RelativeLayout can use :
android:layout_toEndOf="#id/some_view"
android:layout_toStartOf="#id/some_view"
android:layout_above="#id/some_view"
android:layout_below="#id/some_view"
to make sure views lineup correctly in relation to each other. FrameLayout is very similar except it's only using gravity to put display its views (with no relation).
I would also suggest you to take a look at the ConstraintLayout component. ConstraintLayout allows you to create large and complex layouts with a flat view hierarchy (no nested view groups). It's similar to RelativeLayout in that all views are laid out according to relationships between sibling views and the parent layout, but it's more flexible than RelativeLayout and easier to use with Android Studio's Layout Editor.
RelativeLayout based on relation of views. It is a layout manager that helps you arrange your UI elements based on some rule. You can specify things like: align this to parents left edge, place this to the left/right of this elements etc.
FrameLayout allows placements along Z-axis. That is you can stack your view elements one above the other.
RelativeLayout - As the name suggest in this viewgroup, view are placed relative to each other. Most used property of relativelayout are used are
android:layout_toLeftOf="#id/some_view1"
android:layout_toRightOf="#id/some_view2"
android:layout_above="#id/some_view3"
android:layout_below="#id/some_view4"
android:layout_toendof="#id/some_view5"
android:layout_tostartof="#id/some_view6"
View are placeed relative to each other. It is really helpful while developing complex designed.
FrameLayout - It behaves as a single object view are not placed relative to each but as per to the FrameLayout. FrameLayout takes the size of biggest child view.
android:gravity="center_horizontal|center_vertical|bottom"
Using above property child views position is modified.

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