A simple drop down view with built-in animations

DropDownView

A simple drop down view with built-in animations.

Gradle

Ensure your minSdkVersion is 19 or above:

android {
    compileSdkVersion 25
    defaultConfig {
	applicationId "com.anthonyfdev.dropdownviewexample"
	minSdkVersion 19
	targetSdkVersion 25
    }
}

Add jitpack repository to your root build.gradle:

allprojects {
	repositories {
	...
        maven { url 'https://jitpack.io' }
    }
}

Add dependency to app level build.gradle:

dependencies {
    compile 'com.github.AnthonyFermin:DropDownView:1.0.1'
}

Usage

JavaDocs

Add view to xml:

<com.anthonyfdev.dropdownview.DropDownView
    android:id="@+id/drop_down_view"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:containerBackgroundColor="#b71c1c"
    app:overlayColor="#64000000"/>

Note: containerBackgroundColor defaults to colorPrimary (#3F51B5 if you don't have that defined)
and overlayColor defaults to #99000000 (60% alpha on black)

Bind views:

dropDownView = (DropDownView) findViewById(R.id.drop_down_view);
collapsedView = LayoutInflater.from(this).inflate(R.layout.view_my_drop_down_header, null, false);
expandedView = LayoutInflater.from(this).inflate(R.layout.view_my_drop_down_expanded, null, false);

Set header and expanded views to DropDownView:

dropDownView.setHeaderView(collapsedView);
dropDownView.setExpandedView(expandedView);

Call expand or collapse:

collapsedView.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        if (dropDownView.isExpanded()) {
            dropDownView.collapseDropDown();
        } else {
            dropDownView.expandDropDown();
        }
    }
});

Optional DropDownListener:

/**
* A listener that wraps functionality to be performed when the drop down is successfully expanded
* or collapsed.
*/
private final DropDownView.DropDownListener dropDownListener = new DropDownView.DropDownListener() {
	@Override
	public void onExpandDropDown() {
	    adapter.notifyDataSetChanged();
	    ObjectAnimator.ofFloat(headerChevronIV, View.ROTATION.getName(), 180).start();
	}
  
	@Override
	public void onCollapseDropDown() {
	    ObjectAnimator.ofFloat(headerChevronIV, View.ROTATION.getName(), -180, 0).start();
	}
    };
     
...
 
dropDownView.setDropDownListener(dropDownListener);

Done!

GitHub