Android View Stuff

1. Android View Stuff

2. TextViews • Display text • Display images???

3. TextViewDrawables • TextViewsallow drawables to appear to the left of, above, to the right of, and below the text.

4. <?xml version="1.0" encoding="utf-8"?> <LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <TextViewandroid:layout_width="wrap_content" android:layout_height="wrap_content" android:drawableLeft="@drawable/ic_launcher" android:text="Drawable Left" android:layout_margin="10dp"/> <TextViewandroid:layout_width="wrap_content" android:layout_height="wrap_content" android:drawableTop="@drawable/ic_launcher" android:text="Drawable Top" android:layout_margin="10dp"/> <TextViewandroid:layout_width="wrap_content" android:layout_height="wrap_content" android:drawableRight="@drawable/ic_launcher" android:text="Drawable Right" android:layout_margin="10dp"/> <TextViewandroid:layout_width="wrap_content" android:layout_height="wrap_content" android:drawableBottom="@drawable/ic_launcher" android:text="Drawable Bottom" android:layout_margin="10dp"/> </LinearLayout>

5. setError() • Method available to TextView and EditText to display an error message to the user. • This is very useful for user input validation.

6. ImageView • Use this View when you want to display an image in your application. • Many beginners will misuse the ImageView by using the incorrect property.

7. ImageViewsrc property • Use the android:src property to set a drawable as the content of the ImageView. • Don’t use android:background unless you want the image to have a background img.

8. ImageView Example <ImageViewandroid:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/ic_launcher"/>

9. ImageView Example with a background <ImageViewandroid:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/ic_launcher" android:background="#FFFF0000"/>

10. ImageViewscaleType • Control how your image is scaled and positioned inside the ImageView • Useful when your image is too big • Useful when your image is too small

11. ImageViewscaleType : center

12. ImageViewscaleType : centerCrop

13. ImageViewscaleType : centerInside

14. ImageViewscaleType : fitCenter

15. ImageViewscaleType : fitStart

16. ImageViewscaleType : fitEnd

17. ImageViewscaleType : fitXY

18. ImageViewscaleType : matrix

19. ImageViewScaleType Info • http://www.peachpit.com/articles/article.aspx?p=1846580&seqNum=2

20. Android:tint • ImageView’s have an attribute that allows the source image of the view to be tinted by a color.

21. ImageButton • We’re familiar with a Button • Default background provided by the platform • Displays Text • Well Android supports an ImageButton • Looks like a regular button • Default background provided by the platform • Displays an Image

22. Why Buttons are awesome • Android provides a method for giving a button a state list that defines which images should be shown while the button is: • Normal • Focused • Enabled • Disabled • Pressed

23. Hiding the default background on an ImageButton • If you want to use an ImageButton but don’t want to see the default background, you can hide it. • Set the android:background=“#00000000” • Set the android:background=“@android:color/transparent

24. ShapeDrawables • An XML file that defines a geometric shape, including colors and gradients. Creates a ShapeDrawable.

25. <?xml version="1.0" encoding="utf-8"?><shapexmlns:android="http://schemas.android.com/apk/res/android"android:shape=["rectangle" | "oval" | "line" | "ring"] ><cornersandroid:radius="integer"android:topLeftRadius="integer"android:topRightRadius="integer"android:bottomLeftRadius="integer"android:bottomRightRadius="integer"/><gradientandroid:angle="integer"android:centerX="integer"android:centerY="integer"android:centerColor="integer"android:endColor="color"android:gradientRadius="integer"android:startColor="color"android:type=["linear" | "radial" | "sweep"]android:useLevel=["true" | "false"] /><paddingandroid:left="integer"android:top="integer"android:right="integer"android:bottom="integer"/><sizeandroid:width="integer"android:height="integer"/><solidandroid:color="color"/><strokeandroid:width="integer"android:color="color"android:dashWidth="integer"android:dashGap="integer"/></shape>

26. ShapeDrawable Examples

27. ShapeDrawable Examples

28. What is a 9-Patch • An Image that has the capability to specify stretchable regions.

29. Use Case for 9-Patch

30. More Info on 9-Patch • Android 9 Patch Tool • A Simple guide to 9-patch for Android UI