I'm new to programming. I was using Graphical Layout then when I was reading xml file, I saw FrameLayout. Then I searched, but I couldn't find something useful. What is FrameLayout and what does it do?
You use a FrameLayout to stack child views on top of each other, with the most recent child on top of the stack. In the example below, the TextView is the most recent, so it is automatically placed on top of the ImageView.
For example:
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<ImageView
android:id="#+id/backgroundImage"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:scaleType="centerCrop"
android:src="#drawable/bitmapie" />
<TextView
android:id="#+id/descTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_marginTop="70dp"
android:background="#android:color/holo_blue_light"
android:padding="10dp"
android:text="TextView placed at the top of the Imageview"
android:textColor="#android:color/white"
android:textSize="22sp" />
</FrameLayout>
Output:
FrameLayout is the simplest implementation of ViewGroup. Child views are drawn are in a stack, where the latest added view is drawn at the top. Usually you can use one of the next approaches or combine them:
Add a single view hierarchy into FrameLayout
Add multiple children and use android:layout_gravity to navigate them
Another popular approaches of using FrameLayout:
as a Fragment container
as an ancestor of your custom ViewGroup
You can consider the word frame as regular photo frame. What you do with that frame? you can place photos in that frame by one top to another. Same as in FrameLayout we can place views ( Any layout, or widget like button, text, image so on) top of other as #ojonugwa shows you the textview top of the Image.
Are you sure that you googled it?
http://www.tutorialspoint.com/android/android_frame_layout.htm
Frame Layout is designed to block out an area on the screen to display a single item. Generally, FrameLayout should be used to hold a single child view, because it can be difficult to organize child views in a way that's scalable to different screen sizes without the children overlapping each other.
You can, however, add multiple children to a FrameLayout and control
their position within the FrameLayout by assigning gravity to each
child, using the android:layout_gravity attribute.
http://blog.neteril.org/blog/2013/10/10/framelayout-your-best-ui-friend/
The secret of FrameLayout is how it layouts its children. Although normally designed to contain one
item, it will happily stack up other element on top of each other.
Thus FrameLayout is essentially a way to manipulate the Z-order of
views on the screen.
This is super useful for a couple of UI tricks from HUD-like elements
to sliding panels to more complex animated transitions. In this post
we will see an example for each of those.
http://www.learn-android-easily.com/2013/05/frame-layout-in-androis.html
FrameLayout is designed to display a single item at a time. You can
have multiple elements within a FrameLayout but each element will be
positioned based on the top left of the screen. Elements that overlap
will be displayed overlapping. I have created a simple XML layout
using FrameLayout that shows how this works.
Basically it puts one view on top of another for example :
Inflating text on Image
<FrameLayout>
<ImageView>
<Textview>
</FrameLayout>
Related
In the following link: FrameLayout it is written:
FrameLayout is designed to block out an area on the screen to display a single item. Generally, FrameLayout should be used to hold a single child view, because it can be difficult to organize child views in a way that's scalable to different screen sizes without the children overlapping each other.
From the way i understand this quote, it means that it is recommended to add only one child to FrameLayout (although it possible to use more than one in order to make each view to overlap his "brother"). But, i can't understand the use of the FrameLayout only with one child, Let's say a LinearLayout. What is the difference between starting a layout file with a LinearLayout as the root of the xml file (see code 1), or wrapping it with a FrameLayout as the root, and then placing a LinearLayout has is son that will be the father of many other ViewGroup and View (see code 2)?
Code 2:
<FrameLayout
...>
<LinearLayout
...>
<ImageView .... />
<TextView .../>
</LinearLayout>
</FrameLayout>
code 1:
<LinearLayout...>
<ImageView.../>
<TextView.../>
</LinearLayout>
Related question. Answer: RelativeLayout can't do it. I'm asking how to do it anyway, with not just RL, or with something else.
General story: you have a complex layout that would be difficult to adjust, and along comes a request for something to be added, aligning with a nested view.
What is the best approach? A popup with a custom style? (not familiar with those yet)? Spending days changing the whole hierarchy to a single RelativeLayout? A custom Layout class as wrapper?
AbsoluteLayout (deprecated) or FrameLayout with programmatically changed LayoutParams or margins? (this I'd rather avoid, I prefer not to touch onMeasure, etc)
Simplified example (no relation to pic above):
LinearLayout defines relative heights of the elements. I don't know to do it with RelativeLayout.
anExpandableView is something to be animated as sliding from under someBar (here; full-width, but perhaps it may need to align its width, as well as vertical position).
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:animateLayoutChanges="true">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<include
android:id="#+id/topStuff"
layout="#layout/incl_topstuff"
android:layout_width="match_parent"
android:layout_weight="7"
android:layout_height="0dip" />
<include
android:id="#+id/someBar"
layout="#layout/incl_filters_and_stuff"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<include
android:id="#+id/bottomStuff"
layout="#layout/incl_bottomstuff"
android:layout_width="match_parent"
android:layout_height="0dip"
android:layout_weight="10" />
</LinearLayout>
<include
android:id="#+id/anExpandableView"
layout="#layout/incl_filters"
android:visibility="gone"
android:layout_below="#id/someBar"/>
</RelativeLayout>
I know SO has an aversion to general questions, but I don't want an ad-hoc solution. I am asking what to do in cases which would be solved if only a wrapping RelativeLayout would allow alignment to a view that is not a direct sibling.
Putting it simply, RelativeLayout can only measure and layout it's direct children based on each other, but I guess you already knew that.
The only general solution would be to implement your own custom Layout class, which I wouldn't recommend. If I had to guess why RelativeLayout does not traverse the entire layout hierarchy at it's level and below, it's probably for performance reasons.
Unfortunately if you're using RelativeLayouts and LinearLayouts and you want views to be dependent on each other you have to pick one approach and stick to it, either the flat hierarchy of RelativeLayout, or the nested one of LinearLayout.
Based on your example, as far as I know, there is no way to implement weighted views with a RelativeLayout, so you're stuck with using a LinearLayout.
The easiest way to do what you want is to inflate your expandableView in code, align it with the bottom of the RelativeLayout, set it's height and position based on bottomStuff, and animate from there.
If you really want to do it in xml, I can think of one somewhat hacky, ad-hoc approach, but which can can be generalized to mirroring the measurement and layout of any hierarchy with a bit of work.
Create a parallel but invisible LinearLayout that is a sibling of the first one. Give it an empty view with weight 7 on top, an invisible copy of someBar in the middle, then your expandable view under that with weight 10. To have it slide up, either animate the height of the invisible someBar and the weight of the empty view on top towards 0, or remove them/set them to gone and set animateLayoutChanges on your LinearLayout.
I want a ListView to fill the space available to it while still leaving room for a small footer view at the bottom of the screen. I'm trying to use a RelativeLayout to accomplish this and attempted to use the solution discussed at Limit number of rows of listview . The problem I'm running into is I'm using nested Fragments, so my ListView is actually a FrameLayout in my xml then I load a ListFragment into that frame dynamically. Given the nested fragment stipulation, how can I get my FrameLayout to "stackFromBottom" as I would with a ListView? I just need to stop the list from pushing the other View off the bottom of the screen. Thanks for your time all.
Here is the solution I came up with:
<TextView
android:id="#+id/advertisement"
android:layout_width="match_parent"
android:layout_height="30dp"
android:text="Ads will appear here"
android:gravity="center"
android:layout_alignParentBottom="true"/>
<FrameLayout
android:id="#+id/news_frag"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#id/carousel_menu"
android:layout_above="#id/advertisement"/>
The trick was to set both layout_above AND layout_below for the FrameLayout, I had only been setting one and that was apparently allowing the layout to push it off of the screen. Also worth noting is they had to be declared in reverse order of how they actually appear on the page, so that the FrameLayout could properly reference the other View.
I wanna put image in top of View and a listview bottom of it.
what's best and correct way?
LinearLayout?RelativeLayout?
and with which attribute?
layout_gravity="top"?
layout_alignParentTop="true"?
please give me a snipped code and a brief description about:
what's different between layout_gravity="top" and android:layout_alignParentTop="true"?
I wanna put image in top of View and a listview bottom of it. what's
best and correct way?
If you want to place a ListView below an ImageView positioned at the top of the current view then you could use both layouts, it isn't any real difference.
The layour_gravityis used to place the children relative within its parent bounds(the Relativelayout doesn't have this attribute). For example you could use a LinearLayout with orientation vertical which will stack your two children one on top of the other like you want. Also layout_gravity="top" is ignored for a vertical orientated LinearLayout as it doesn't make sense, so you could remove it from the layout completely:
<LinearLayout android:orientation="vertical">
<!-- the layout_gravity is useless int this case and could be removed-->
<ImageView android:layout_gravity="top"/>
<ListView />
</LinearLayout>
layout_alignParentTop is a placement rule for children of RelativeLayout(only for this type of layout!) which tells them to position aligning the top of the children with the top of the parent RelativeLayout. In this case, to stack the children you would do:
<RelativeLayout>
<!-- you could remove the layout_alignParentTop attribute because by default the Relativelayout will position it's children there -->
<ImageView android:id="#+id/imageId" android:layout_alingParentTop="true" />
<!-- Position this child below the other -->
<ListView android:layout_below="#id/imageId"/>
</RelativeLayout>
I have many activities with a scrollview inside a tablelayout. However, it is necessary a small design change, so I have to put a black transparent view over the whole screen from the top to the bottom. Is it possible to do it in the tablelayout or the scrollview?
RelativeLayout allows for easy overlapping of views. You'll have to adjust the existing views in your app because it doesn't do anything automatically.
EDIT:
A quick way to do this would be to take your existing view (the ScrollView) that is already organized and put it in a top-level RelativeLayout. Then, all you have to do is add new view inside the RelativeLayout with the width and height both set to MATCH_PARENT. The result should be the black transparent view will be visible over the ScrollView.
I normally use FrameLayout to achieve any kind of 'layering' of views.
<FrameLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
//your existing layout
<View
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#33000000" />
</FrameLayout>
As DeeV said, you can probably use RelativeLayout in a similar way, but you might have to set additional attributes on its children to achieve this.