1. Android Sensor Programming
CIS 694/EEC 693 Android Sensor Programming
Lecture 7
Wenbing Zhao
Department of Electrical Engineering and Computer Science
Cleveland State University
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Android Sensor Programming

2. Android Sensor Programming
User Interface
ScrollView
Adapting to Display Orientation
Action Bar
Creating UI Programmatically
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Android Sensor Programming

3. Android Sensor Programming
ScrollView
A ScrollView is a special type of FrameLayout in that it enables users to scroll through a list of views that occupy more space than the physical display
The ScrollView can contain only one child view or ViewGroup, which normally is a LinearLayout
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Android Sensor Programming

4. Android Sensor Programming
ScrollView
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Button 3" />
<EditText
android:layout_height="600dp" />
android:text="Button 4" />
android:text="Button 5" />
</LinearLayout>
</ScrollView>
<ScrollView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="
<LinearLayout
android:layout_height="wrap_content"
android:orientation="vertical"
android:focusable="true"
android:focusableInTouchMode="true">
<Button
android:text="Button 1" />
android:text="Button 2" />
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Android Sensor Programming

5. Android Sensor Programming
ScrollView
Scroll down to see this:
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Android Sensor Programming

6. Adapting to Display Orientation
Two techniques to handle changes in screen orientation:
Anchoring—The easiest way is to “anchor” your views to the four edges of the screen. When the screen orientation changes, the views can anchor neatly to the edges
Resizing and repositioning—Resizing each and every view according to the current screen orientation
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Android Sensor Programming

7. Anchoring Views with RelativeLayout
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Bottom Left"
android:layout_alignParentStart="true"
android:layout_alignParentBottom="true" />
android:text="Bottom Right"
android:layout_alignParentEnd="true"
android:layout_width="fill_parent"
android:text="Middle"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true" />
</RelativeLayout>
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Top Left"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true" />
android:text="Top Right"
android:layout_alignParentTop="true"
android:layout_alignParentEnd="true" />
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Android Sensor Programming

8. Anchoring Views with RelativeLayout
layout_alignParentStart—Aligns the view to the left of the parent view
layout_alignParentEnd—Aligns the view to the right of the parent view
layout_alignParentTop—Aligns the view to the top of the parent view
layout_alignParentBottom—Aligns the view to the bottom of the parent view
layout_centerVertical—Centers the view vertically within its parent view
layout_centerHorizontal—Centers the view horizontally within its parent view
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Android Sensor Programming

9. Android Sensor Programming
Anchoring Views with RelativeLayout
Homework #8: Build an app that has the following output
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Android Sensor Programming

10. Detecting Orientation Changes
Programmatically detect the current orientation of your activity: getResources()
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if(getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE){
Log.d("StateInfo", "Landscape");
}else if(getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT){
Log.d("StateInfo", "Portrait"); }
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Android Sensor Programming

11. Android Sensor Programming
Controlling the Orientation of the Activity
Sometimes, you might want the app to be displayed in only a certain orientation
Using setRequestOrientation() method
Or Using android:screenOrientation attribute on the <activity> element in AndroidManifest
import android.content.pm.ActivityInfo;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//---change to landscape mode---
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE); }
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Android Sensor Programming

12. Android Sensor Programming
Using android:screenOrientation attribute on the <activity> element in AndroidManifest
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="
package="com.username.orientations">
<application
android:allowBackup="true"
android:supportsRtl="true"
<activity android:name=".MainActivity"
android:screenOrientation="landscape">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
Two other values that you can specify in the android:screenOrientation attribute:
portrait—Portrait mode
sensor—Based on the accelerometer (default)
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Android Sensor Programming

13. Android Sensor Programming
Action Bar
Action Bar displays the application icon and the activity title
Optionally, on the right side of the Action Bar are action items
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Android Sensor Programming

14. Android Sensor Programming
Adding Action Items
Using Android Studio, create a new Android project and name it MyActionBar
When prompted, select a Basic Activity as the template
Modify the MainActivity.java file as follows
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
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Android Sensor Programming

15. Android Sensor Programming
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Snackbar.make(view,"Replace with your own action",
Snackbar.LENGTH_LONG).setAction("Action", null).show(); }
});
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
//getMenuInflater().inflate(R.menu.menu_main, menu);
CreateMenu(menu);
return true;
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Android Sensor Programming

16. Android Sensor Programming
private void CreateMenu(Menu menu) {
MenuItem mnu1 = menu.add(0, 0, 0, "Item 1"); {
mnu1.setIcon(R.mipmap.ic_launcher);
mnu1.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM); }
MenuItem mnu2 = menu.add(0, 1, 1, "Item 2");
mnu2.setIcon(R.mipmap.ic_launcher);
mnu2.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
MenuItem mnu3 = menu.add(0, 2, 2, "Item 3");
mnu3.setIcon(R.mipmap.ic_launcher);
mnu3.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
MenuItem mnu4 = menu.add(0, 3, 3, "Item 4");
mnu4.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
MenuItem mnu5 = menu.add(0, 4, 4,"Item 5");
mnu5.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
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Android Sensor Programming

17. Android Sensor Programming
private boolean MenuChoice(MenuItem item) {
switch (item.getItemId()) {
case 0:
Toast.makeText(this, "You clicked on Item 1", Toast.LENGTH_LONG).show();
return true;
case 1:
Toast.makeText(this, "You clicked on Item 2",Toast.LENGTH_LONG).show();
case 2:
Toast.makeText(this, "You clicked on Item 3",Toast.LENGTH_LONG).show();
case 3:
Toast.makeText(this, "You clicked on Item 4",Toast.LENGTH_LONG).show();
case 4:
Toast.makeText(this, "You clicked on Item 5",Toast.LENGTH_LONG).show(); }
return false;
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Android Sensor Programming

18. Android Sensor Programming
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true; }
return MenuChoice(item);
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Android Sensor Programming

19. Android Sensor Programming
Overflow menu
Clicking a menu item
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Android Sensor Programming

20. Android Sensor Programming
Homework #9: Modify the ActionBar app by by altering the behavior when each action item is clicked in the following ways:
When item1 through item4 is clicked, a TextView should be displayed on the screen at different locations (that is, the TextViews should not be at the same location or overlap with each other).
When item5 is clicked, all existing TextViews that have been added to the screen should be cleared.
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Android Sensor Programming

21. Android Sensor Programming
Creating UI Programmatically
Using Android Studio, create a new Android project and name it UICode
In the MainActivity.java file, add the bold statements in the following code:
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutCompat;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;
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Android Sensor Programming

22. Android Sensor Programming
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
LinearLayoutCompat.LayoutParams params =
new LinearLayoutCompat.LayoutParams(
LinearLayoutCompat.LayoutParams.WRAP_CONTENT,
LinearLayoutCompat.LayoutParams.WRAP_CONTENT);
LinearLayout layout = new LinearLayout(this); //---create a layout---
layout.setOrientation(LinearLayout.VERTICAL);
TextView tv = new TextView(this); //---create a textview---
tv.setText("This is a TextView"); tv.setLayoutParams(params);
Button btn = new Button(this); //---create a button---
btn.setText("This is a Button"); btn.setLayoutParams(params);
layout.addView(tv); //---adds the textview---
layout.addView(btn); //---adds the button---
//---create a layout param for the layout---
LinearLayoutCompat.LayoutParams layoutParam =
LinearLayoutCompat.LayoutParams.WRAP_CONTENT );
this.addContentView(layout, layoutParam); }
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Android Sensor Programming

23. Android Sensor Programming
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Android Sensor Programming