How to set shape's opacity?
In general you just have to define a slightly transparent color when creating the shape.
You can achieve that by setting the colors alpha channel.
#FF000000
will get you a solid black whereas #00000000
will get you a 100% transparent black (well it isn't black anymore obviously).
The color scheme is like this #AARRGGBB
there A stands for alpha channel, R stands for red, G for green and B for blue.
The same thing applies if you set the color in Java. There it will only look like 0xFF000000
.
UPDATE
In your case you'd have to add a solid
node. Like below.
<?xml version="1.0" encoding="UTF-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/shape_my">
<stroke android:width="4dp" android:color="#636161" />
<padding android:left="20dp"
android:top="20dp"
android:right="20dp"
android:bottom="20dp" />
<corners android:radius="24dp" />
<solid android:color="#88000000" />
</shape>
The color here is a half transparent black.
use this code below as progress.xml:
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item android:id="@android:id/background">
<shape>
<corners android:radius="5dip" />
<gradient
android:startColor="#ff9d9e9d"
android:centerColor="#ff5a5d5a"
android:centerY="0.75"
android:endColor="#ff747674"
android:angle="270"
/>
</shape>
</item>
<item android:id="@android:id/secondaryProgress">
<clip>
<shape>
<solid android:color="#00000000" />
</shape>
</clip>
</item>
<item android:id="@android:id/progress">
<clip>
<shape>
<solid android:color="#00000000" />
</shape>
</clip>
</item>
</layer-list>
where:
- "progress" is current progress before the thumb and "secondaryProgress" is the progress after thumb.
- color="#00000000" is a perfect transparency
- NOTE: the file above is from default android res and is for 2.3.7, it is available on android sources at: frameworks/base/core/res/res/drawable/progress_horizontal.xml. For newer versions you must find the default drawable file for the seekbar corresponding to your android version.
after that use it in the layout containing the xml:
<SeekBar
android:id="@+id/myseekbar"
...
android:progressDrawable="@drawable/progress"
/>
you can also customize the thumb by using a custom icon seek_thumb.png:
android:thumb="@drawable/seek_thumb"