How do you create an Android View Pager with a dots indicator?
You can check out my library to handle your request : https://github.com/tommybuonomo/dotsindicator
In your XML layout
<com.tbuonomo.viewpagerdotsindicator.DotsIndicator
android:id="@+id/dots_indicator"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
app:dotsColor="@color/colorPrimary"
app:dotsSize="16dp"
app:dotsWidthFactor="3"
/>
In your Java code
dotsIndicator = (DotsIndicator) findViewById(R.id.dots_indicator);
viewPager = (ViewPager) findViewById(R.id.view_pager);
adapter = new ViewPagerAdapter();
viewPager.setAdapter(adapter);
dotsIndicator.setViewPager(viewPager);
First Create a layout, in that give one LinerLayout for Dots which show over your View Pager
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v4.view.ViewPager
android:id="@+id/view_pager"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
<LinearLayout
android:id="@+id/pager_dots"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_marginBottom="10dp"
android:background="@android:color/transparent"
android:gravity="center_horizontal"
android:orientation="horizontal">
</LinearLayout>
</RelativeLayout>
After that create 2 drawables
1. Unselected Drawable
<?xml version="1.0" encoding="utf-8"?>
<shape android:shape="oval" xmlns:android="http://schemas.android.com/apk/res/android">
<solid android:color="@android:color/transparent"/>
<size android:width="12dp" android:height="12dp"/>
<stroke android:width="1dp" android:color="#ffffff"/>
</shape>
2. Selected Drawable
<?xml version="1.0" encoding="utf-8"?>
<shape android:shape="oval" xmlns:android="http://schemas.android.com/apk/res/android">
<solid android:color="@android:color/transparent"/>
<size android:width="12dp" android:height="12dp"/>
<stroke android:width="1dp" android:color="#000000"/>
</shape>
After that set adapter
private LinearLayout llPagerDots;
private ViewPager viewPager;
private ArrayList<String> eventImagesUrl;
private HomeViewPagerAdapter homeViewPagerAdapter;
private ImageView[] ivArrayDotsPager;
public void setUpViewPager() {
viewPager = (ViewPager) findViewById(R.id.view_pager);
llPagerDots = (LinearLayout) findViewById(R.id.pager_dots);
homeViewPagerAdapter = new HomeViewPagerAdapter(mContext, eventImagesUrl);
viewPager.setAdapter(homeViewPagerAdapter);
setupPagerIndidcatorDots();
ivArrayDotsPager[0].setImageResource(R.drawable.page_indicator_selected);
viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
for (int i = 0; i < ivArrayDotsPager.length; i++) {
ivArrayDotsPager[i].setImageResource(R.drawable.page_indicator_unselected);
}
ivArrayDotsPager[position].setImageResource(R.drawable.page_indicator_selected);
}
@Override
public void onPageScrollStateChanged(int state) {
}
});
}
Create a method setupPagerIndidcatorDots() :
private void setupPagerIndidcatorDots() {
ivArrayDotsPager = new ImageView[eventImagesUrl.size()];
for (int i = 0; i < ivArrayDotsPager.length; i++) {
ivArrayDotsPager[i] = new ImageView(getActivity());
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
params.setMargins(5, 0, 5, 0);
ivArrayDotsPager[i].setLayoutParams(params);
ivArrayDotsPager[i].setImageResource(R.drawable.page_indicator_unselected);
//ivArrayDotsPager[i].setAlpha(0.4f);
ivArrayDotsPager[i].setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
view.setAlpha(1);
}
});
llPagerDots.addView(ivArrayDotsPager[i]);
llPagerDots.bringToFront();
}
All we need are: ViewPager, TabLayout and 2 drawables for selected and default dots.
Firstly, we have to add TabLayout
to our screen layout, and connect it with ViewPager
. We can do this in two ways:
Nested TabLayout
in ViewPager
<androidx.viewpager.widget.ViewPager
android:id="@+id/photos_viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.google.android.material.tabs.TabLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
</androidx.viewpager.widget.ViewPager>
In this case
TabLayout
will be automatically connected withViewPager
, butTabLayout
will be next toViewPager
, not over it.
Separate TabLayout
<androidx.viewpager.widget.ViewPager
android:id="@+id/photos_viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
<com.google.android.material.tabs.TabLayout
android:id="@+id/tab_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
In this case, we can put
TabLayout
anywhere, but we have to connectTabLayout
withViewPager
programmatically
ViewPager pager = (ViewPager) view.findViewById(R.id.photos_viewpager);
PagerAdapter adapter = new PhotosAdapter(getChildFragmentManager(), photosUrl);
pager.setAdapter(adapter);
TabLayout tabLayout = (TabLayout) view.findViewById(R.id.tab_layout);
tabLayout.setupWithViewPager(pager, true);
Once we created our layout, we have to prepare our dots. So we create three files: selected_dot.xml
, default_dot.xml
and tab_selector.xml
.
selected_dot.xml
<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item>
<shape
android:innerRadius="0dp"
android:shape="ring"
android:thickness="8dp"
android:useLevel="false">
<solid android:color="@color/colorAccent"/>
</shape>
</item>
</layer-list>
default_dot.xml
<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item>
<shape
android:innerRadius="0dp"
android:shape="ring"
android:thickness="8dp"
android:useLevel="false">
<solid android:color="@android:color/darker_gray"/>
</shape>
</item>
</layer-list>
tab_selector.xml
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="@drawable/selected_dot"
android:state_selected="true"/>
<item android:drawable="@drawable/default_dot"/>
</selector>
Now we need to add only 3 lines of code to TabLayout
in our XML layout.
app:tabBackground="@drawable/tab_selector"
app:tabGravity="center"
app:tabIndicatorHeight="0dp"