org.gnome.gtk
Class Button

java.lang.Object
  org.freedesktop.bindings.Proxy
      org.gnome.glib.Object
          org.gnome.gtk.Object
              org.gnome.gtk.Widget
                  org.gnome.gtk.Container
                      org.gnome.gtk.Bin
                          org.gnome.gtk.Button

Direct Known Subclasses:

ColorButton, FontButton, LinkButton, ScaleButton, ToggleButton

public class Button
extends Bin

A Widget that emits a signal when clicked on. Button can hold any just about any other Widget as its child. The most commonly used child is a Label, and there are convenience methods to help you just create a button with the given text automatically, notably the Button(String) constructor.

Since Button is a Bin it strictly only has one child. Internally, however, it may have both an icon image and some text (which is the look commonly seen in the action buttons in Dialog boxes). You can add such an image to a Button by calling setImage(); this works alongside and with setLabel(). The machinery within Button will manage creating the necessary internal structure (HBoxes, Alignments, etc).

Since:

4.0.0

Author:

Andrew Cowie, Vreixo Formoso, Mario Torre

Nested Class Summary

static interface

Button.CLICKED Event generated when a user presses and releases a button, causing it to activate.

Nested classes/interfaces inherited from class org.gnome.gtk.Widget

Widget.BUTTON_PRESS_EVENT, Widget.BUTTON_RELEASE_EVENT, Widget.ENTER_NOTIFY_EVENT, Widget.EXPOSE_EVENT, Widget.FOCUS_IN_EVENT, Widget.FOCUS_OUT_EVENT, Widget.HIDE, Widget.KEY_PRESS_EVENT, Widget.KEY_RELEASE_EVENT, Widget.LEAVE_NOTIFY_EVENT, Widget.UNMAP_EVENT, Widget.VISIBILITY_NOTIFY_EVENT

Constructor Summary

Button()
Create an "empty" button to use as a Container.

Button(Stock stock)
Create a new Button with a Label and Image from a StockItem.

Button(java.lang.String text)
Create a button with a Label as its child.

Method Summary

void	connect(Button.CLICKED handler) Hook up a handler to receive "clicked" events on this Button.
void	emitClicked() Cause a CLICKED signal to be emitted.
float	getAlignmentX() Get the horizontal alignment of the child Widget within this Button.
float	getAlignmentY() Get the vertical alignment of the child Widget within this Button.
Image	getImage() Get the Image associated with this Button.
java.lang.String	getLabel() Get the text showing on the Button.
ReliefStyle	getRelief() Get the relief style in use around this Button.
void	setAlignment(float xalign, float yalign) Set the alignment of the child Widget within the Button.
void	setImage(Image image) Paint an arbitrary Image over this Button.
void	setLabel(java.lang.String text) Set the text showing in the Button.
void	setRelief(ReliefStyle style) Set the "relief" style used to determine how the edges of this Button will be decorated.

Methods inherited from class org.gnome.gtk.Bin

getChild

Methods inherited from class org.gnome.gtk.Container

add, getChildren, remove, setBorderWidth

Methods inherited from class org.gnome.gtk.Widget

activate, connect, connect, connect, connect, connect, connect, connect, connect, connect, connect, connect, connect, getAllocation, getHasFocus, getParent, getRequisition, getToplevel, getWindow, grabFocus, hide, modifyBackground, modifyText, setCanFocus, setSensitive, setSizeRequest, setTooltipMarkup, setTooltipText, show, showAll

Methods inherited from class org.freedesktop.bindings.Proxy

toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Button

public Button()

Create an "empty" button to use as a Container. You'll need to add() the Widget which will be the Button's child.

For most uses setImage() and setLabel() will more than take care of things; they can be used together.

Since:

4.0.0

Button

public Button(Stock stock)

Create a new Button with a Label and Image from a StockItem. By using a system StockItem, the newly created Button with use the same Label and Image as other GNOME applications. To ensure consistent look-n-feel between applications, it is highly recommend that you use provided StockItems whenever possible.

Parameters:

stock - The stock item that will determine the text and icon of the Button.

Since:

4.0.4

Button

public Button(java.lang.String text)

Create a button with a Label as its child. Simply specify the text you want for the Label and a Button will be created accordingly. This is quite a common case - in fact, we're generally more used to thinking of Buttons as being Labels that you can press than as arbitrary Widget Containers.

Note that you can use setImage() on a Button created this way.

Parameters:

text - the text you wish on the Label that will be created in the Button.

Since:

4.0.0

Method Detail

connect

public void connect(Button.CLICKED handler)

Hook up a handler to receive "clicked" events on this Button. A typical example of how this is used is as follows:

 Button b;
              
 b.connect(new Button.CLICKED() {
     public void onClicked(Button source) {
         // do something!
     }
 }
 

You can of course create a subclass of Button.CLICKED and then use instances of it if you have highly complicated algorithms to implement.

If you implement Button.CLICKED in the class you're currently working on, then you use a technique called "self-delegation" which can sometimes work well;

 b.connect(this);
 

Since:

4.0.0

emitClicked

public void emitClicked()

Cause a CLICKED signal to be emitted.

Since:

4.0.6

getAlignmentX

public float getAlignmentX()

Get the horizontal alignment of the child Widget within this Button. The return will range from 0.0 (full left) to 1.0 (full right).

getAlignmentY

public float getAlignmentY()

Get the vertical alignment of the child Widget within this Button. The return will range from 0.0 (top) to 1.0 (bottom).

getImage

public Image getImage()

Get the Image associated with this Button.

Returns:

the Widget associated with this Button using the setImage() method, or null if the Button doesn't have one set.

Since:

4.0.5

getLabel

public java.lang.String getLabel()

Get the text showing on the Button.

Returns:

the text of the Label, or null if the no-arg constructor was used and you've just got an arbitrary Widget-containing-Button, not the more usual Button-with-Label.

Since:

4.0.0

getRelief

public ReliefStyle getRelief()

Get the relief style in use around this Button.

Since:

4.0.1

setAlignment

public void setAlignment(float xalign,
                         float yalign)

Set the alignment of the child Widget within the Button. This has no impact unless the child of the Button is a Misc (which of course the default child, a Label, is).

Parameters:

xalign - from 0.0f representing fully left-aligned through 1.0f representing fully right-aligned.

yalign - from 0.0f for fully top-aligned through 1.0f for fully bottom-aligned

setImage

public void setImage(Image image)

Paint an arbitrary Image over this Button. If this is used on an empty Button then the Button will be the size of the Image and will what is activatable. On the other hand, you can use this in conjunction with setLabel() in which case you will get an icon on the left and the label text on the right.

Since:

4.0.5

setLabel

public void setLabel(java.lang.String text)

Set the text showing in the Button.

If you created an empty Button without a Label using Button(), this will create a Label nested in an Alignment for you. That won't work if you create an empty Button then put a custom Widget in place with add() instead of employing this method and/or setImage()).

Since:

4.0.0

setRelief

public void setRelief(ReliefStyle style)

Set the "relief" style used to determine how the edges of this Button will be decorated. The default is NORMAL which results in a Button just as you would expect, screaming out to be pressed! There are two other variations, see ReliefStyle for details.

Since:

4.0.1