Android - An Open Handset Alliance Project

android.widget
public class

android.widget.Button

java.lang.Object
	android.view.View			Drawable.Callback KeyEvent.Callback
		android.widget.TextView
			android.widget.Button

Button represents a push-button widget. Push-buttons can be pressed, or clicked, by the user to perform an action. A typical use of a push-button in an activity would be the following:

 public class MyActivity extends Activity {
     protected void onCreate(Bundle icicle) {
         super.onCreate(icicle);

         setContentView(R.layout.content_layout_id);

         final Button button = (Button) findViewById(R.id.button_id);
         button.setOnClickListener(new Button.OnClickListener() {
             public void onClick(View v) {
                 // Perform action on click
             }
         });
     }
 }

XML attributes

See Button Attributes, TextView Attributes, View Attributes

Known Direct Subclasses

CompoundButton

Known Indirect Subclasses

CheckBox, RadioButton

Summary

XML Attributes inherited from class android.widget.TextView

Attribute name	Related methods
android:autoLink	setAutoLinkMask(int)	Controls whether links such as urls and email addresses are automatically found and converted to clickable links.
android:autoText	setInputMethod(InputMethod)	If set, specifies that this TextView has a textual input method and automatically corrects some common spelling errors.
android:bufferType	setText(CharSequence,TextView.BufferType)	Determines what the minimum type that getText() will return.
android:capitalize	setInputMethod(InputMethod)	If set, specifies that this TextView has a textual input method and should automatically capitalize what the user types.
android:cursorVisible	setCursorVisible(boolean)	Makes the cursor visible (the default) or invisible Must be a boolean value, either "`true`" or "`false`".
android:digits	setInputMethod(InputMethod)	If set, specifies that this TextView has a numeric input method and that these specific characters are the ones that it will accept.
android:editable		If set, specifies that this TextView has an input method.
android:ems	setEms(int)	Makes the TextView be exactly this many ems wide Must be an integer value, such as "`100`".
android:freezesText	setFreezesText(boolean)	If set, the text view will include its current complete text inside of its frozen icicle in addition to meta-data such as the current cursor position.
android:gravity	setGravity(int)	Vertical gravity (top, center_vertical, bottom) when the text is smaller than the view.
android:height	setHeight(int)	Makes the TextView be exactly this many pixels tall.
android:hint	setHint(int)	Hint text to display when the text is empty.
android:includeFontPadding	setIncludeFontPadding(boolean)	Leave enough room for ascenders and descenders instead of using the font ascent and descent strictly.
android:inputMethod	setInputMethod(InputMethod)	If set, specifies that this TextView should use the specified input method (specified by fully-qualified class name).
android:lines	setLines(int)	Makes the TextView be exactly this many lines tall Must be an integer value, such as "`100`".
android:maxEms	setMaxEms(int)	Makes the TextView be at most this many ems wide Must be an integer value, such as "`100`".
android:maxHeight	setMaxHeight(int)	Makes the TextView be at most this many pixels tall Must be a dimension value, which is a floating point number appended with a unit such as "`14.5sp`".
android:maxLength	setFilters(InputFilter)	Set an input filter to constrain the text length to the specified number.
android:maxLines	setMaxLines(int)	Makes the TextView be at most this many lines tall Must be an integer value, such as "`100`".
android:maxWidth	setMaxWidth(int)	Makes the TextView be at most this many pixels wide Must be a dimension value, which is a floating point number appended with a unit such as "`14.5sp`".
android:minEms	setMinEms(int)	Makes the TextView be at least this many ems wide Must be an integer value, such as "`100`".
android:minHeight	setMinHeight(int)	Makes the TextView be at least this many pixels tall Must be a dimension value, which is a floating point number appended with a unit such as "`14.5sp`".
android:minLines	setMinLines(int)	Makes the TextView be at least this many lines tall Must be an integer value, such as "`100`".
android:minWidth	setMinWidth(int)	Makes the TextView be at least this many pixels wide Must be a dimension value, which is a floating point number appended with a unit such as "`14.5sp`".
android:numeric	setInputMethod(InputMethod)	If set, specifies that this TextView has a numeric input method.
android:password	setTransformationMethod(TransformationMethod)	Whether the characters of the field are displayed as password dots instead of themselves.
android:phoneNumber	setInputMethod(InputMethod)	If set, specifies that this TextView has a phone number input method.
android:scrollHorizontally	setHorizontallyScrolling(boolean)	Whether the text is allowed to be wider than the view (and therefore can be scrolled horizontally).
android:selectAllOnFocus	setSelectAllOnFocus(boolean)	If the text is selectable, select it all when the view takes focus instead of moving the cursor to the start or end.
android:shadowColor	setShadowLayer(float,float,float,int)	Place a shadow of the specified color behind the text.
android:shadowDx	setShadowLayer(float,float,float,int)	Horizontal offset of the shadow.
android:shadowDy	setShadowLayer(float,float,float,int)	Vertical offset of the shadow.
android:shadowRadius	setShadowLayer(float,float,float,int)	Radius of the shadow.
android:singleLine	setTransformationMethod(TransformationMethod)	Constrains the text to a single horizontally scrolling line instead of letting it wrap onto multiple lines, and advances focus instead of inserting a newline when you press the enter key.
android:text	setText(CharSequence)	Text to display.
android:textAlign	setAlignment(Layout.Alignment)	Horizontal text alignment: start (default), center, or end.
android:textColor	setTextColor(ColorStateList)	Text color.
android:textColorHighlight	setHiliteColor(int)	Color of the text selection highlight.
android:textColorHint	setHintTextColor(int)	Color of the hint text.
android:textScaleX	setTextScaleX(float)	Sets the horizontal scaling factor for the text Must be a floating point value, such as "`1.2`".
android:textSize	setTextSize(float)	Size of the text.
android:textStyle	setTypeface(Typeface)	Style (bold, italic, bolditalic) for the text.
android:typeface	setTypeface(Typeface)	Typeface (normal, sans, serif, monospace) for the text.
android:width	setWidth(int)	Makes the TextView be exactly this many pixels wide.

XML Attributes inherited from class android.view.View

Attribute name	Related methods
android:background	setBackground(int)	A drawable to use as the background.
android:clickable	setClickable(boolean)	Defines whether this view reacts to click events.
android:drawingCacheQuality	setDrawingCacheQuality(int)	Defines the quality of translucent drawing caches.
android:fadingEdge	setVerticalFadingEdgeEnabled(boolean)	Defines which edges should be fadeded on scrolling.
android:fadingEdgeLength	getVerticalFadingEdgeLength()	Defines the length of the fading edges.
android:fitStatusBar		Boolean internal attribute to adjust view layout based on the status bar location.
android:focusType	setFocusType(int)	Sets the circumstances under which this view will take focus.
android:focusable	setFocusable(boolean)	Boolean that controls whether a view can take focus.
android:focusableInTouchMode	setFocusableInTouchMode(boolean)	Boolean that controls whether a view can take focus while in touch mode.
android:freezeDisabled	setFreezeDisabled(boolean)	If set, no icicle will be saved for this view when it is being frozen.
android:id	setId(int)	Supply an identifier name for this view, to later retrieve it with View.findViewById() or Activity.findViewById().
android:nextFocusDown		Defines the next view to give focus to when the next focus is FOCUS_DOWN If the reference refers to a view that does not exist or is part of a hierarchy that is invisible, a RuntimeException will result when the reference is accessed.
android:nextFocusLeft		Defines the next view to give focus to when the next focus is FOCUS_LEFT.
android:nextFocusRight		Defines the next view to give focus to when the next focus is FOCUS_RIGHT If the reference refers to a view that does not exist or is part of a hierarchy that is invisible, a RuntimeException will result when the reference is accessed.
android:nextFocusUp		Defines the next view to give focus to when the next focus is FOCUS_UP If the reference refers to a view that does not exist or is part of a hierarchy that is invisible, a RuntimeException will result when the reference is accessed.
android:padding	setPadding(int,int,int,int)	Sets the padding, in pixels, of all four edges.
android:paddingBottom	setPadding(int,int,int,int)	Sets the padding, in pixels, of the bottom edge; see padding.
android:paddingLeft	setPadding(int,int,int,int)	Sets the padding, in pixels, of the left edge; see padding.
android:paddingRight	setPadding(int,int,int,int)	Sets the padding, in pixels, of the right edge; see padding.
android:paddingTop	setPadding(int,int,int,int)	Sets the padding, in pixels, of the top edge; see padding.
android:scrollX		The initial horizontal scroll offset, in pixels.
android:scrollY		The initial vertical scroll offset, in pixels.
android:scrollbarDefaultDelayBeforeFade		Delay in milliseconds before the scrollbars disappear.
android:scrollbarFadeDuration		Duration in milliseconds of the fade when the scrollbars disappear.
android:scrollbarSize		Sets the width of vertical scrollbars and height of horizontal scrollbars.
android:scrollbarThumbHorizontal		Drawable for horizontal scrollbars' thumb.
android:scrollbarThumbVertical		Drawable for vertical scrollbars' thumb.
android:scrollbarTrackHorizontal		Drawable for horizontal scrollbars' track.
android:scrollbarTrackVertical		Drawable for vertical scrollbars' track.
android:scrollbars		Defines which scrollbars should be displayed on scrolling or not.
android:visibility	setVisibility(int)	Controls the initial visibility of the view.

Constants inherited from class android.view.View

DRAWING_CACHE_QUALITY_AUTO, DRAWING_CACHE_QUALITY_HIGH, DRAWING_CACHE_QUALITY_LOW, FOCUS_BACKWARD, FOCUS_DOWN, FOCUS_FORWARD, FOCUS_LEFT, FOCUS_RIGHT, FOCUS_UP, GONE, INVISIBLE, NORMAL_FOCUS, NO_ID, VIEW_LOG_TAG, VISIBLE, WEAK_FOCUS

			Value
int	DRAWING_CACHE_QUALITY_AUTO	Enables automatic quality mode for the drawing cache.	0	0x00000000
int	DRAWING_CACHE_QUALITY_HIGH	Enables high quality mode for the drawing cache.	1048576	0x00100000
int	DRAWING_CACHE_QUALITY_LOW	Enables low quality mode for the drawing cache.	524288	0x00080000
int	FOCUS_BACKWARD	Use with focusSearch(int).	1	0x00000001
int	FOCUS_DOWN	Use with focusSearch(int).	130	0x00000082
int	FOCUS_FORWARD	Use with focusSearch(int).	2	0x00000002
int	FOCUS_LEFT	Use with focusSearch(int).	17	0x00000011
int	FOCUS_RIGHT	Use with focusSearch(int).	66	0x00000042
int	FOCUS_UP	Use with focusSearch(int).	33	0x00000021
int	GONE	This view is invisible, and it doesn't take any space for layout purposes.	8	0x00000008
int	INVISIBLE	This view is invisible, but it still takes up space for layout purposes.	4	0x00000004
int	NORMAL_FOCUS	This view wants keystrokes.	0	0x00000000
int	NO_ID	Used to mark a View that has no ID.	-1	0xffffffff
String	VIEW_LOG_TAG	The logging tag used by this class with android.util.Log.	"View"
int	VISIBLE	This view is visible.	0	0x00000000
int	WEAK_FOCUS	This view wants keystrokes, but only if none of its children has focus.	2	0x00000002

Fields inherited from class android.view.View

mBottom, mContext, mLayoutParams, mLeft, mLocation, mOnClickListener, mOnFocusChangeListener, mOnLongClickListener, mOnPopulateContextMenuListener, mPaddingBottom, mPaddingLeft, mPaddingRight, mPaddingTop, mParent, mRight, mScrollX, mScrollY, mTag, mTop

protected		int	mBottom	The distance in pixels from the top edge of this view's parent to the bottom edge of this view.
protected		Context	mContext	The application environment this view lives in.
protected		LayoutParams	mLayoutParams	The layout parameters associated with this view and used by the parent ViewGroup to determine how this view should be laid out.
protected		int	mLeft	The distance in pixels from the left edge of this view's parent to the left edge of this view.
protected	final	int[]	mLocation	Used to store a pair of coordinates, for instance returned values returned by getLocationInWindow(int[]).
protected		OnClickListener	mOnClickListener	Listener used to dispatch click events.
protected		OnFocusChangeListener	mOnFocusChangeListener	Listener used to dispatch focus change events.
protected		OnLongClickListener	mOnLongClickListener	Listener used to dispatch long click events.
protected		OnPopulateContextMenuListener	mOnPopulateContextMenuListener	Listener used to build the context menu.
protected		int	mPaddingBottom	The bottom padding in pixels, that is the distance in pixels between the bottom edge of this view and the bottom edge of its content.
protected		int	mPaddingLeft	The left padding in pixels, that is the distance in pixels between the left edge of this view and the left edge of its content.
protected		int	mPaddingRight	The right padding in pixels, that is the distance in pixels between the right edge of this view and the right edge of its content.
protected		int	mPaddingTop	The top padding in pixels, that is the distance in pixels between the top edge of this view and the top edge of its content.
protected		ViewParent	mParent	The parent this view is attached to.
protected		int	mRight	The distance in pixels from the left edge of this view's parent to the right edge of this view.
protected		int	mScrollX	The offset, in pixels, by which the content of this view is scrolled horizontally.
protected		int	mScrollY	The offset, in pixels, by which the content of this view is scrolled vertically.
protected		Object	mTag	The view's tag.
protected		int	mTop	The distance in pixels from the top edge of this view's parent to the top edge of this view.

Public Constructors

					Button(Context context)
					Button(Context context, AttributeSet attrs, Map inflateParams)
					Button(Context context, AttributeSet attrs, Map inflateParams, int defStyle)

Methods inherited from class android.widget.TextView

		void	addTextChangedListener(TextWatcher watcher)
			Adds a TextWatcher to the list of those whose methods are called whenever this TextView's text changes.
final		void	append(CharSequence text)
			Convenience method: Append the specified text to the TextView's display buffer, upgrading it to BufferType.EDITABLE if it was not already editable.
		void	append(CharSequence text, int start, int end)
			Convenience method: Append the specified text slice to the TextView's display buffer, upgrading it to BufferType.EDITABLE if it was not already editable.
		int	computeHorizontalScrollRange()
			Compute the horizontal range that the horizontal scrollbar represents.
		void	computeScroll()
			Called by a parent to request that a child update its values for mScrollX and mScrollY if necessary.
		int	computeVerticalScrollRange()
			Compute the vertical range that the vertical scrollbar represents.
		void	debug(int depth)
			Prints information about this view in the log output, with the tag VIEW_LOG_TAG.
		void	drawableStateChanged()
			This function is called whenever the state of the view changes in such a way that it impacts the state of drawables being shown.
final		int	getAutoLinkMask()
			Gets the autolink mask of the text.
		int	getBaseline()
			Return the offset of the widget's text baseline from the widget's top boundary.
final		int	getCurrentHintTextColor()
			Return the current color selected to paint the hint text.
final		int	getCurrentTextColor()
			Return the current color selected for normal text.
		boolean	getDefaultEditable()
			Subclasses override this to specify default editability.
		MovementMethod	getDefaultMovementMethod()
			Subclasses override this to specify a default movement method.
		InputFilter[]	getFilters()
			Returns the current list of input filters.
		boolean	getFreezesText()
			Return whether this text view is including its entire text contents in frozen icicles.
final		ColorStateList	getHintTextColors()
			Return the color used to paint the hint text.
final		InputMethod	getInputMethod()
final		Layout	getLayout()
		int	getLineBounds(int line, Rect bounds)
			Return the baseline for the specified line (0...getLineCount() - 1) If bounds is not null, return the top, left, right, bottom extents of the specified line in it.
		int	getLineCount()
			Return the number of lines of text, or 0 if the internal Layout has not been built.
		int	getLineHeight()
final		MovementMethod	getMovementMethod()
		TextPaint	getPaint()
		int	getPaintFlags()
		int	getSelectionEnd()
			Convenience for getSelectionEnd(CharSequence).
		int	getSelectionStart()
			Convenience for getSelectionStart(CharSequence).
		CharSequence	getText()
			Return the text the TextView is displaying.
	static	int	getTextColor(Context context, StyledAttributes attrs, int def)
			Returns the default color from the TextView_textColor attribute from the AttributeSet, if set, or the default color from the TextAppearance_textColor from the TextView_textAppearance attribute, if TextView_textColor was not set directly.
final		ColorStateList	getTextColors()
			Return the set of text colors.
	static	ColorStateList	getTextColors(Context context, StyledAttributes attrs)
			Returns the TextView_textColor attribute from the Resources.StyledAttributes, if set, or the TextAppearance_textColor from the TextView_textAppearance attribute, if TextView_textColor was not set directly.
		float	getTextScaleX()
		float	getTextSize()
final		TransformationMethod	getTransformationMethod()
		Typeface	getTypeface()
		boolean	hasSelection()
			Return true iff there is a selection inside this text view.
		int	length()
			Returns the length, in characters, of the text managed by this TextView
		void	makeNewLayout(int w, Metrics boring)
			The width passed in is now the desired layout width, not the full view width with padding.
		void	onDraw(Canvas canvas)
			Implement this to do your drawing.
		void	onFocusChanged(boolean focused, int direction, Rect previouslyFocusedRect)
			Called by the view system when the focus state of this view changes.
		Parcelable	onFreeze()
			Hook allowing a view to generate a representation of its internal state that can later be used to create a new instance with that same state.
		boolean	onKeyDown(int keyCode, KeyEvent event)
			Default implementation of KeyEvent.Callback.onKeyMultiple(): perform press of the view when KEYCODE_DPAD_CENTER or KEYCODE_NEWLINE is released, if the view is enabled and clickable.
		boolean	onKeyUp(int keyCode, KeyEvent event)
			Default implementation of KeyEvent.Callback.onKeyMultiple(): perform clicking of the view when KEYCODE_DPAD_CENTER or KEYCODE_NEWLINE is released.
		void	onMeasure(int widthMeasureSpec, int heightMeasureSpec)
			Measure the view and its content to determine the measured width and the measured height.
		void	onTextChanged(CharSequence text, int start, int before, int after)
			This method is called when the text is changed, in case any subclasses would like to know.
		void	onThaw(Parcelable state)
			Hook allowing a view to re-apply a representation of its internal state that had previously been generated by onFreeze().
		boolean	onTouchEvent(MotionEvent event)
			Implement this method to handle touch screen motion events.
		boolean	onTrackballEvent(MotionEvent event)
			Implement this method to handle trackball motion events.
		void	onWindowFocusChanged(boolean hasWindowFocus)
			Called when the window containing this view gains or loses focus.
		void	removeTextChangedListener(TextWatcher watcher)
			Removes the specified TextWatcher from the list of those whose methods are called whenever this TextView's text changes.
		void	setAlignment(Alignment align)
			Sets the alignment of this view's text.
final		void	setAutoLinkMask(int mask)
			Sets the autolink mask of the text.
		void	setCursorVisible(boolean visible)
			Set whether the cursor is visible.
		void	setEms(int ems)
			Makes the TextView exactly this many ems wide
		void	setFilters(InputFilter[] filters)
			Sets the list of input filters that will be used if the buffer is Editable.
		void	setFreezesText(boolean freezesText)
			Control whether this text view saves its entire text contents when freezing to an icicle, in addition to dynamic state such as cursor position.