## GtkButton

GtkButton — A widget that creates a signal when clicked on

## Synopsis

    #include <gtk/gtk.h>

                GtkButton;
    GtkWidget*  gtk_button_new                  (void);
    GtkWidget*  gtk_button_new_with_label       (const gchar *label);
    GtkWidget*  gtk_button_new_with_mnemonic    (const gchar *label);
    GtkWidget*  gtk_button_new_from_stock       (const gchar *stock_id);
    void        gtk_button_pressed              (GtkButton *button);
    void        gtk_button_released             (GtkButton *button);
    void        gtk_button_clicked              (GtkButton *button);
    void        gtk_button_enter                (GtkButton *button);
    void        gtk_button_leave                (GtkButton *button);
    void        gtk_button_set_relief           (GtkButton *button,
                                                 GtkReliefStyle newstyle);
    GtkReliefStyle gtk_button_get_relief        (GtkButton *button);
    const gchar* gtk_button_get_label           (GtkButton *button);
    void        gtk_button_set_label            (GtkButton *button,
                                                 const gchar *label);
    gboolean    gtk_button_get_use_stock        (GtkButton *button);
    void        gtk_button_set_use_stock        (GtkButton *button,
                                                 gboolean use_stock);
    gboolean    gtk_button_get_use_underline    (GtkButton *button);
    void        gtk_button_set_use_underline    (GtkButton *button,
                                                 gboolean use_underline);
    void        gtk_button_set_focus_on_click   (GtkButton *button,
                                                 gboolean focus_on_click);
    gboolean    gtk_button_get_focus_on_click   (GtkButton *button);
    void        gtk_button_set_alignment        (GtkButton *button,
                                                 gfloat xalign,
                                                 gfloat yalign);
    void        gtk_button_get_alignment        (GtkButton *button,
                                                 gfloat *xalign,
                                                 gfloat *yalign);
    void        gtk_button_set_image            (GtkButton *button,
                                                 GtkWidget *image);
    GtkWidget*  gtk_button_get_image            (GtkButton *button);

## Object Hierarchy

      GObject
       +----GtkObject
             +----GtkWidget
                   +----GtkContainer
                         +----GtkBin
                               +----GtkButton
                                     +----GtkToggleButton
                                     +----GtkColorButton
                                     +----GtkFontButton
                                     +----GtkOptionMenu

## Implemented Interfaces

GtkButton implements AtkImplementorIface.

## Properties

      "focus-on-click"       gboolean              : Read / Write
      "image"                GtkWidget             : Read / Write
      "label"                gchararray            : Read / Write / Construct
      "relief"               GtkReliefStyle        : Read / Write
      "use-stock"            gboolean              : Read / Write / Construct
      "use-underline"        gboolean              : Read / Write / Construct
      "xalign"               gfloat                : Read / Write
      "yalign"               gfloat                : Read / Write

## Style Properties

      "child-displacement-x" gint                  : Read
      "child-displacement-y" gint                  : Read
      "default-border"       GtkBorder             : Read
      "default-outside-border" GtkBorder             : Read
      "displace-focus"       gboolean              : Read

## Signal Prototypes

    "activate"  void        user_function      (GtkButton *widget,
                                                gpointer user_data);
    "clicked"   void        user_function      (GtkButton *button,
                                                gpointer user_data);
    "enter"     void        user_function      (GtkButton *button,
                                                gpointer user_data);
    "leave"     void        user_function      (GtkButton *button,
                                                gpointer user_data);
    "pressed"   void        user_function      (GtkButton *button,
                                                gpointer user_data);
    "released"  void        user_function      (GtkButton *button,
                                                gpointer user_data);

## Description

The GtkButton widget is generally used to attach a function to that is called when the button is pressed. The various signals and how to use them are outlined below.

The GtkButton widget can hold any valid child widget. That is it can hold most any other standard GtkWidget. The most commonly used child is the GtkLabel.

## Details

### GtkButton

    typedef struct _GtkButton GtkButton;

This should not be accessed directly. Use the accessor functions below.

### gtk_button_new ()

    GtkWidget*  gtk_button_new                  (void);

Creates a new GtkButton widget. To add a child widget to the button, use `gtk_container_add()`.

Returns : | The newly created GtkButton widget.

### gtk_button_new_with_label ()

    GtkWidget*  gtk_button_new_with_label       (const gchar *label);

Creates a GtkButton widget with a GtkLabel child containing the given text.

`label` : | The text you want the GtkLabel to hold.
Returns : | The newly created GtkButton widget.

### gtk_button_new_with_mnemonic ()

    GtkWidget*  gtk_button_new_with_mnemonic    (const gchar *label);

Creates a new GtkButton containing a label. If characters in `label` are preceded by an underscore, they are underlined. If you need a literal underscore character in a label, use '__' (two underscores). The first underlined character represents a keyboard accelerator called a mnemonic. Pressing Alt and that key activates the button.

`label` : | The text of the button, with an underscore in front of the mnemonic character
Returns : | a new GtkButton

### gtk_button_new_from_stock ()

    GtkWidget*  gtk_button_new_from_stock       (const gchar *stock_id);

Creates a new GtkButton containing the image and text from a stock item. Some stock ids have preprocessor macros like GTK_STOCK_OK and GTK_STOCK_APPLY.

If `stock_id` is unknown, then it will be treated as a mnemonic label (as for `gtk_button_new_with_mnemonic()`).

`stock_id` : | the name of the stock item
Returns : | a new GtkButton

### gtk_button_pressed ()

    void        gtk_button_pressed              (GtkButton *button);

Emits a GtkButton::pressed signal to the given GtkButton.

`button` : | The GtkButton you want to send the signal to.

### gtk_button_released ()

    void        gtk_button_released             (GtkButton *button);

Emits a GtkButton::released signal to the given GtkButton.

`button` : | The GtkButton you want to send the signal to.

### gtk_button_clicked ()

    void        gtk_button_clicked              (GtkButton *button);

Emits a GtkButton::clicked signal to the given GtkButton.

`button` : | The GtkButton you want to send the signal to.

### gtk_button_enter ()

    void        gtk_button_enter                (GtkButton *button);

Emits a GtkButton::enter signal to the given GtkButton.

`button` : | The GtkButton you want to send the signal to.

### gtk_button_leave ()

    void        gtk_button_leave                (GtkButton *button);

Emits a GtkButton::leave signal to the given GtkButton.

`button` : | The GtkButton you want to send the signal to.

### gtk_button_set_relief ()

    void        gtk_button_set_relief           (GtkButton *button,
                                                 GtkReliefStyle newstyle);

Sets the relief style of the edges of the given GtkButton widget. Three styles exist, GTK_RELIEF_NORMAL, GTK_RELIEF_HALF, GTK_RELIEF_NONE. The default style is, as one can guess, GTK_RELIEF_NORMAL.

`button` : | The GtkButton you want to set relief styles of.
`newstyle` : | The GtkReliefStyle as described above.

### gtk_button_get_relief ()

    GtkReliefStyle gtk_button_get_relief        (GtkButton *button);

Returns the current relief style of the given GtkButton.

`button` : | The GtkButton you want the GtkReliefStyle from.
Returns : | The current GtkReliefStyle

### gtk_button_get_label ()

    const gchar* gtk_button_get_label           (GtkButton *button);

Fetches the text from the label of the button, as set by `gtk_button_set_label()`. If the label text has not been set the return value will be `NULL`. This will be the case if you create an empty button with `gtk_button_new()` to use as a container.

`button` : | a GtkButton
Returns : | The text of the label widget. This string is owned by the widget and must not be modified or freed.

### gtk_button_set_label ()

    void        gtk_button_set_label            (GtkButton *button,
                                                 const gchar *label);

Sets the text of the label of the button to `str`. This text is also used to select the stock item if `gtk_button_set_use_stock()` is used.

This will also clear any previously set labels.

`button` : | a GtkButton
`label` : | a string

### gtk_button_get_use_stock ()

    gboolean    gtk_button_get_use_stock        (GtkButton *button);

Returns whether the button label is a stock item.

`button` : | a GtkButton
Returns : | `TRUE` if the button label is used to select a stock item instead of being used directly as the label text.

### gtk_button_set_use_stock ()

    void        gtk_button_set_use_stock        (GtkButton *button,
                                                 gboolean use_stock);

If true, the label set on the button is used as a stock id to select the stock item for the button.

`button` : | a GtkButton
`use_stock` : | `TRUE` if the button should use a stock item

### gtk_button_get_use_underline ()

    gboolean    gtk_button_get_use_underline    (GtkButton *button);

Returns whether an embedded underline in the button label indicates a mnemonic. See `gtk_button_set_use_underline()`.

`button` : | a GtkButton
Returns : | `TRUE` if an embedded underline in the button label indicates the mnemonic accelerator keys.

### gtk_button_set_use_underline ()

    void        gtk_button_set_use_underline    (GtkButton *button,
                                                 gboolean use_underline);

If true, an underline in the text of the button label indicates the next character should be used for the mnemonic accelerator key.

`button` : | a GtkButton
`use_underline` : | `TRUE` if underlines in the text indicate mnemonics

### gtk_button_set_focus_on_click ()

    void        gtk_button_set_focus_on_click   (GtkButton *button,
                                                 gboolean focus_on_click);

Sets whether the button will grab focus when it is clicked with the mouse. Making mouse clicks not grab focus is useful in places like toolbars where you don't want the keyboard focus removed from the main area of the application.

`button` : | a GtkButton
`focus_on_click` : | whether the button grabs focus when clicked with the mouse

Since 2.4

### gtk_button_get_focus_on_click ()

    gboolean    gtk_button_get_focus_on_click   (GtkButton *button);

Returns whether the button grabs focus when it is clicked with the mouse. See `gtk_button_set_focus_on_click()`.

`button` : | a GtkButton
Returns : | `TRUE` if the button grabs focus when it is clicked with the mouse.

Since 2.4

### gtk_button_set_alignment ()

    void        gtk_button_set_alignment        (GtkButton *button,
                                                 gfloat xalign,
                                                 gfloat yalign);

Sets the alignment of the child. This property has no effect unless the child is a GtkMisc or a GtkAligment.

`button` : | a GtkButton
`xalign` : | the horizontal position of the child, 0.0 is left aligned, 1.0 is right aligned
`yalign` : | the vertical position of the child, 0.0 is top aligned, 1.0 is bottom aligned

Since 2.4

### gtk_button_get_alignment ()

    void        gtk_button_get_alignment        (GtkButton *button,
                                                 gfloat *xalign,
                                                 gfloat *yalign);

Gets the alignment of the child in the button.

`button` : | a GtkButton
`xalign` : | return location for horizontal alignment
`yalign` : | return location for vertical alignment

Since 2.4

### gtk_button_set_image ()

    void        gtk_button_set_image            (GtkButton *button,
                                                 GtkWidget *image);

Set the image of `button` to the given widget. Note that it depends on the gtk-button-images setting whether the image will be displayed or not.

`button` : | a GtkButton
`image` : | a widget to set as the image for the button

Since 2.6

### gtk_button_get_image ()

    GtkWidget*  gtk_button_get_image            (GtkButton *button);

Gets the widget that is currenty set as the image of `button`. This may have been explicitly set by `gtk_button_set_image()` or constructed by `gtk_button_new_from_stock()`.

`button` : | a GtkButton
Returns : | a GtkWidget or `NULL` in case there is no image

Since 2.6

## Properties

### The "`focus-on-click`" property

      "focus-on-click"       gboolean              : Read / Write

Whether the button grabs focus when it is clicked with the mouse.

Default value: TRUE

### The "`image`" property

      "image"                GtkWidget             : Read / Write

Child widget to appear next to the button text.

### The "`label`" property

      "label"                gchararray            : Read / Write / Construct

Text of the label widget inside the button, if the button contains a label widget.

Default value: NULL

### The "`relief`" property

      "relief"               GtkReliefStyle        : Read / Write

The border relief style.

Default value: GTK_RELIEF_NORMAL

### The "`use-stock`" property

      "use-stock"            gboolean              : Read / Write / Construct

If set, the label is used to pick a stock item instead of being displayed.

Default value: FALSE

### The "`use-underline`" property

      "use-underline"        gboolean              : Read / Write / Construct

If set, an underline in the text indicates the next character should be used for the mnemonic accelerator key.

Default value: FALSE

### The "`xalign`" property

      "xalign"               gfloat                : Read / Write

If the child of the button is a GtkMisc or GtkAlignment, this property can be used to control it's horizontal alignment. 0.0 is left aligned, 1.0 is right aligned.

Allowed values: [0,1]

Default value: 0.5

Since 2.4

### The "`yalign`" property

      "yalign"               gfloat                : Read / Write

If the child of the button is a GtkMisc or GtkAlignment, this property can be used to control it's vertical alignment. 0.0 is top aligned, 1.0 is bottom aligned.

Allowed values: [0,1]

Default value: 0.5

Since 2.4

## Style Properties

### The "`child-displacement-x`" style property

      "child-displacement-x" gint                  : Read

How far in the x direction to move the child when the button is depressed.

Default value: 0

### The "`child-displacement-y`" style property

      "child-displacement-y" gint                  : Read

How far in the y direction to move the child when the button is depressed.

Default value: 0

### The "`default-border`" style property

      "default-border"       GtkBorder             : Read

Extra space to add for CAN_DEFAULT buttons.

### The "`default-outside-border`" style property

      "default-outside-border" GtkBorder             : Read

Extra space to add for CAN_DEFAULT buttons that is always drawn outside the border.

### The "`displace-focus`" style property

      "displace-focus"       gboolean              : Read

Whether the child_displacement_x/child_displacement_y properties should also affect the focus rectangle.

Default value: FALSE

Since 2.6

## Signals

### The "activate" signal

    void        user_function                  (GtkButton *widget,
                                                gpointer user_data);

The "activate" signal on GtkButton is an action signal and emitting it causes the button to animate press then release. Applications should never connect to this signal, but use the "clicked" signal.

`widget` : | the object which received the signal.
`user_data` : | user data set when the signal handler was connected.

### The "clicked" signal

    void        user_function                  (GtkButton *button,
                                                gpointer user_data);

Emitted when a button clicked on by the mouse and the cursor stays on the button. If the cursor is not on the button when the mouse button is released, the signal is not emitted.

`button` : | the object which received the signal.
`user_data` : | user data set when the signal handler was connected.

### The "enter" signal

    void        user_function                  (GtkButton *button,
                                                gpointer user_data);

Emitted when the mouse cursor enters the region of the button.

`button` : | the object which received the signal.
`user_data` : | user data set when the signal handler was connected.

### The "leave" signal

    void        user_function                  (GtkButton *button,
                                                gpointer user_data);

Emitted when the mouse cursor leaves the region of the button.

`button` : | the object which received the signal.
`user_data` : | user data set when the signal handler was connected.

### The "pressed" signal

    void        user_function                  (GtkButton *button,
                                                gpointer user_data);

Emitted when the button is initially pressed.

`button` : | the object which received the signal.
`user_data` : | user data set when the signal handler was connected.

### The "released" signal

    void        user_function                  (GtkButton *button,
                                                gpointer user_data);

Emitted when a button which is pressed is released, no matter where the mouse cursor is.

`button` : | the object which received the signal.
`user_data` : | user data set when the signal handler was connected.