BUTTON Gadget

Members

Methods

Command

The BUTTON command defines a button, and specifies its position, tag or pixmap, callback text and control attribute.

You can define the BUTTON to be either PML-controlled, or core-code controlled using the gadget qualifier attribute control type, with values "PML" or "CORE".

The files defining any pixmaps should be specified in the form's default constructor method using the gadget's AddPixmap() method. Refer to Icons from Resource Files for further information.

A Button type Linklabel provides a purely textual button presentation, often used to indicate a link to some application item, for example, a hyperlink to a file, a link to an associated form. An Example of the Linklabel gadget is shown on the example form in Fold up Gadget Link Example Form with Fold-up panels, NumericInput and Linklabel gadgets.

The tag text is shown in a different color to all other gadget's tag text. The link label gadget highlights by underlining when the mouse cursor passes over it. Pressing it causes a SELECT event to be raised and runs any associated call back.

Notes:

1. The Button has subtypes Normal, Toggle and Linklabel.

2. Linklabels are Buttons and so they do cause validation of any modified text fields of the form whenever they are pressed.

3. Linklabels:

   1. cannot have pixmaps assigned to them

   2. don't support change of background color

   3. don't support 'pressed' and 'not pressed' value

   4. are not enclosed in a box

   5. can have popup menus (though this is not recommended)

   6. don't have Control Types, for example: OK, CANCEL.

4. The sub-type of a Button gadget can be queried using the Button's Subtype method.

   .--------<-------.

   / |

   >-BUTTON gname -+- LINKLabel -+-- tagtext -------|

   | +-- <fgpos> -------|

   | +-- CALLback text -|

   | +-- TOOLTIP text --|

   | +-- <fganch> ------|

   | +-- <fgdock> ------|

   | +-- CORE ---------* Core managed gadget

   | | .------<-----.

   | |/ |

   | +- FORM fname -|

   | +- <vshap> ----*

   | |

   | +- TOOLTIP text -.

   | '----------------'-->

   |

   | .--------<----------.

   +-- TOGGLE -./ |

   '-----------+- tagtext -----------|

   +- <fgpos> -----------|

   +- CALLback text -----|

   +- TOOLTIP text ------|

   +- <fganch> ----------|

   +- <fgdock> ----------|

   +- CORE --------------| Core managed gadget

   +- BACKGround <colno>-|

   +- PIXMAP <vshap> ----*

   | .------<-----.

   |/ |

   +- FORM fname -|

   +- <vshap> ----*

   |

   +- OK -----.

   +- APPLY --|

   +- CANCEL -|

   +- RESET --|

   +- HELP ---|

   '----------+- TOOLTIP text -.

   '----------------'-->

   Note: It is bad practice to place one gadget on top of another. This may lead to gadgets being obscured.

   Defaults:

   If no tag is specified, the tag defaults to the gadget’s gname. The control attribute is unset unless you specifically enter OK, APPLY, HELP, CANCEL or RESET. The default values for anchoring is ANCHOR = Left + Top.

The Pixmaps associated with Button gadgets can be changed after the gadgets have been displayed on a form.

Method syntax is:

AddPixmap( !pixmap1 is STRING )

AddPixmap( !pixmap1 is STRING, !pixmap2 is STRING )

Where: !pixmap is a string holding the file pathname of the required .png file, for example:

%pmllib%\png\camera.png

!pixmap1 shows the Un-selected state of the gadget, and pixmap2 shows the Selected state.

Notes: It is recommended that when you define the gadget you set its size to encompass the largest pixmap which you will later add. Failure to do this may give rise to unexpected behavior.

Historically, you could add a third pixmap which was used when the gadget was de-activated. This practice is no longer necessary as the gadget pixmapped is automatically greyed-out on de-activation.