I found a description about the difference of transparent and translucent. These are the important parts:
What does translucent mean? If you were writing about a pane of glass,
but that pane of glass was frosty, darkly colored, or very dirty, you
would use translucent.
What does transparent mean? If you were writing about a pane of glass,
and that piece of glass was perfectly clear, you would use
transparent. Something that is transparent allows all light to pass
through it. Clean air and the windshield of a car are transparent.
If you want to understand this deeply then look here.
I want to make a ViewGroup translucent in Android. In a video I found how to make an Activity translucent. What they do is defining the following styles and colors:
<color name="transparent_green_color">#8800ff00</color>
<style name="TranslucentGreen" parent="android:Theme.Translucent">
<item name="android:windowBackground">#color/transparent_green_color</item>
</style>
And then in the manifest the within the application tag they add this new style as a theme:
<application
android:theme="#style/TranslucentGreen"
...>
...
</application>
What I want to do is NOT to make an Activity translucent but to make a ViewGroup translucent.
My layout is structured like this:
<FrameLayout>
<RelativeLayout>
...
</RelativeLayout>
<RelativeLayout>
...
</RelativeLayout>
</FrameLayout>
The second RelativeLayout shall be translucent and the first one shall be visible a bit through the translucent RelativeLayout. How to do that?
Using the Blurry library solved my problem. So if the second ViewGroup (in my case second RelativeLayout) has to be at the top and the first one has to shine through translucent, then you need to call something like:
Blurry.with(context).radius(25).sampling(2).onto(viewGroup);
and then you have the desired effect. For going back to the old view state without translucency you can just use this method:
Blurry.delete(viewGroup)
on the desired view. I like that library because it's very compact.
If you are not able to use external libraries you should maybe start with this Medium article. It works with RenderScript and Bitmap class. Bu It shall be possible to create Bitmaps from ViewGroups.
Related
I want my menu items on the BottomNavigationBar to have text-only labels with no icon. Unfortunately, it looks like design_bottom_navigation_item.xml always has a 24x24dp space reserved for the icon, with no publicly-exposed way to set it to gone. And even after getting past that, the label layout is set to a layout_gravity of bottom|center_horizontal, and it doesn't look like there's a way to programatically set layout_gravity to centered.
What is the fastest, easiest way to achieve the goal of a text-only menu item on the bottom nav bar? I'm thinking I can do this by creating a custom version of the item layout, then subclassing BottomNavigationItemView, BottomNavigationMenuView, and BottomNavigationView to specify that custom layout... but that seems like an awful lot of work for one little change. Am I missing something simpler?
dont put iandroid:icon property to your item
Just use the code below. I tried hard to do this easy way but failed.Then I made an alternative. Just use transparent color instead of icon drawble
<item
android:icon="#android:color/transparent"
android:id="#+id/navigation_id"
android:title="title" />
Add this in your dimens file. Then you can add padding according to your navigation view size.
<dimen name="design_bottom_navigation_height"tools:override="true">30dp</dimen>
I've recently updated my phone to Android Marshmallow and ran my existing app on it, but noticed a difference in color behavior: When applying changes to the background of a view (drawable), all views that share the same background (reference) will also the same changes applied. While previously, this was not the case.
Example
In this example, I have a two views with the same background color, and I want to change the alpha level of one of both views.
First we define the views in the layout:
<LinearLayout
android:id="#+id/test1"
android:orientation="horizontal"
android:layout_width="50dp"
android:layout_height="50dp"
android:background="#color/testColor2">
</LinearLayout>
<LinearLayout
android:id="#+id/test2"
android:orientation="horizontal"
android:layout_width="50dp"
android:layout_height="50dp"
android:background="#color/testColor1"
android:layout_marginLeft="5dp">
</LinearLayout>
Both views share the same background color or drawable:
<color name="testColor1">#3F51B5</color>
<color name="testColor2">#3F51B5</color>
The result looks like this:
Now we are going to change one of the two background, like this:
LinearLayout test1 = (LinearLayout) findViewById(R.id.test1);
LinearLayout test2 = (LinearLayout) findViewById(R.id.test2);
test1.getBackground().setAlpha(80);
Which results in this:
However, the desired and expected result is obviously this:
Download the sample project here.
A few thoughs:
When setting the Alpha level trough XML, this behavior does not apply.
It does not matter if both views refer to a different color definition in colors.xml (like in the example), refer to the same color definition of both have the same color (hex) directly in the view's xml file.
Question
How can I make changes to a view's background without this affecting other views that share the same background. Preferably while still being able to use a background that directly refers to a color defined in the color's xml file
Most likely the class of each view's background and constantstate are
the same object. It seems as if the two color resources have been
"merged" somewhere -- meaning they have shared ConstantState. Maybe in
the Resources class' caching? I would've expected them to stay
separate since they're different resources (albeit with the same color
value), but apparently not.
– Snild Dolkow
The ColorDrawable's state stores alpha, so any changes to one will change the others. To prevent this, you can first call mutate() on the drawable, separating the two drawables (by making a copy of the state).
In the example, this would result in using test1.getBackground().mutate().setAlpha(80); instead of directly applying the alpha.
I am wanting to create help overlays like the ones you see when ICS loads for the first time or in apps like ES File Explorer or Apex Launcher (there are more, but I can't think of them right now). Is this just a relative layout with one view sitting on top of the other? I haven't been able to find any sample code for doing such a thing. Anyone know how this is done or have any ideas?
Let's assume you ordinarily would call setContentView(R.layout.main), but on first run, you want to have this overlay.
Step #1: Create a FrameLayout in Java code and pass that to setContentView().
Step #2: Use LayoutInflater to inflate R.layout.main into the FrameLayout.
Step #3: Use LayoutInflater to inflate the overlay into the FrameLayout.
Step #4: When the user taps the button (or whatever) to dismiss the overlay, call removeView() to remove the overlay from the FrameLayout.
Since the overlay is a later child of the FrameLayout, it will float over top of the contents of R.layout.main.
"Coach mark" is "Help overlay" in UX talk :-)
coach_mark.xml is your coach mark layout
coach_mark_master_view is the id of the top most view (root) in coach_mark.xml
public void onCoachMark(){
final Dialog dialog = new Dialog(this);
dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
dialog.getWindow().setBackgroundDrawable(new ColorDrawable(android.graphics.Color.TRANSPARENT));
dialog.setContentView(R.layout.coach_mark);
dialog.setCanceledOnTouchOutside(true);
//for dismissing anywhere you touch
View masterView = dialog.findViewById(R.id.coach_mark_master_view);
masterView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
dialog.dismiss();
}
});
dialog.show();
}
Adding sample of coach_mark.xml (to this excellent solution given by Oded Breiner), so its easy for ppl to copy & paste to see working example quickly.
Sample of coach_mark.xml here, change the -> drawable/coach_marks to your image:
coach_mark.xml
<?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:orientation="vertical"
android:id="#+id/coach_mark_master_view">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent" >
<ImageView
android:id="#+id/coach_marks_image"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerInParent="true"
android:layout_gravity="center_horizontal"
android:src="#drawable/coach_marks" />
</RelativeLayout>
</LinearLayout>
And optionally use this theme to remove padding:
<style name="WalkthroughTheme" parent="Theme.AppCompat">
<item name="android:windowIsTranslucent">true</item>
<item name="android:windowBackground">#android:color/transparent</item>
<item name="android:windowContentOverlay">#null</item>
<item name="android:windowNoTitle">true</item>
<item name="android:backgroundDimEnabled">false</item>
</style>
You can do that pretty quickly. You add, for exemple a LinearLayout where you put a picture with alpha which correspond to your help information and what do you want to draw like an overlay. In you xml of your activity you put this layout in a RelativeLayout after the layout of your activity with the Gone visibility. When you want to draw the help information, you just neeed to set this visibility to visible.
I hope, I'm clear, if you have any question,I'm be please to answer them.
See my another answer how programmatically show an overlay layout on top of the current activity. Activity's layout.xml does not need to know anything about the overlay skin. You can put overlay semi-transparent, cover only part of the screen, one or more textview and buttons on it...
How to overlay a button programmically?
create res/layout/paused.xml RelativeLayout template or use any layout toplevel
create a function to show overlay skin
key is to get handle to layout.xml, use LayoutInflater class to parse xml to view object, add overlay view to current layout structure
My example uses a timer to destroy overlay object by completely removing it from the view structure. This is probably what you want as well to get rid of it without a trace.
My goal was that main activities are not aware of any overlay skin, overlays come and go, many different overlays, still able to use overlay1.xml text files as a template, and content should programmatically be updated. I do pretty much what CommonsWare told us my post shows the actual program code to get started.
disclaimer: OPs "Thanks for your input. This is how I pictured it being done. I have to give credit to the answer below" comment does not mean my answer but CommonsWare answer. Stackoverflow have changed post orderings.
I try to make a ExpandableListView where the group headers are drawn inverse. There is no problem with changing the text color, size etc. via XML. I even found out how to use the system defaults like
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
style="#android:style/TextAppearance.Medium.Inverse"
/>
But for the background color?! I don't understand why these styles don't include background color information?!
Of course I could use a direct color, but I look for good default background attributes or styles. Like "style/Background.For.TextAppearance.Medium.Inverse" ;-)
What would be a good solution? So that for the dark themed devices I get white/gray, and for the white themed I get black?
Or should I simply use R.color.background_light?
Greetings, Joerg
PS: First question here ;-) Thanx to all the people answering here the last months and years: You great people made it much more easier for me to find a re-entrance in programming after 12 years break ;-)
As you observe, the styles with "TextAppearance" in their name only affect the foreground text attributes of the view. They are appropriate for the android:textAppearance attribute. The styles with "Widget" in their names define all the UI properties and will work in a style attribute, but Android doesn't define a "Widget.TextView.Inverse" style.
When I wanted to display an console-like log as an inverse text view, I used the following XML:
<TextView
android:textAppearance="#style/TextAppearance.AppCompat.Small.Inverse"
android:background="?android:colorForeground"
... />
It uses the theme's foreground color as the background for the view. With a dark theme it displays dark text on white, and in a light theme it displays light text on black.
I have an activity that I would like to occur in a dialog. Is there anyway to do this from code, instead of in the manifest? I tried to do this, but it seemed to have no effect.
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setTheme(R.style.Theme_Dialog);
}
Also, the activity contains a webview and when it starts out as a dialog it's got a small amount of content and the dialog is only like 100px tall. When content fills in it scrolls inside a tiny 100px tall window in the dialog. How do I make the dialog take up more vertical space?
You can easily accomplish this via XML. Just use an XML named 'themes.xml', and place it in the values folder.
Here's a basic example, which implements a custom background:
<resources>
<style name="my_theme" parent="#android:style/Theme.Dialog">
<item name="android:windowBackground">#drawable/custom_background</item>
</style>
</resources>
You'll also need to add the following line to the desired activity section of the manifest:
android:theme="#style/my_theme"
PS: I realize this is an old thread, but hopefully it helps someone nonetheless :)
I'm not aware of a way to set the dialog theme from code.
The dialog is basically as big as it needs to be to contain the content, so if you want it to be bigger you need to make some component in your view larger. Perhaps you can set the hieght of the webview to something larger. Note, use dpi, not px!
that's the solution, you can apply a theme via code, thanks to this guy :)
wasn't aware of this constructor myself
https://stackoverflow.com/a/1975508/371749