fltk/FL/Fl_Multi_Label.H

97 lines
3.8 KiB
C++

//
// Multi-label header file for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2015 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file. If this
// file is missing or damaged, see the license at:
//
// https://www.fltk.org/COPYING.php
//
// Please see the following page on how to report bugs and issues:
//
// https://www.fltk.org/bugs.php
//
#ifndef Fl_Multi_Label_H
#define Fl_Multi_Label_H
class Fl_Widget;
struct Fl_Menu_Item;
/** Allows a mixed text and/or graphics label to be applied to an Fl_Menu_Item or Fl_Widget.
Most regular FLTK widgets now support the ability to associate both images and text
with a label but some special cases, notably the non-widget Fl_Menu_Item objects, do not.
Fl_Multi_Label may be used to create menu items that have an icon and text, which would
not normally be possible for an Fl_Menu_Item.
For example, Fl_Multi_Label is used in the New->Code submenu in fluid, and others.
\image html Fl_Multi_Label-menu-item.png "Menu items with icons using Fl_Multi_Label"
\image latex Fl_Multi_Label-menu-item.png "Menu items with icons using Fl_Multi_Label" width=4cm
Each Fl_Multi_Label holds two elements, labela and labelb; each may hold either a
text label (const char*) or an image (Fl_Image*). When displayed, labela is drawn first
and labelb is drawn immediately to its right.
More complex labels might be constructed by setting labelb as another Fl_Multi_Label and
thus chaining up a series of label elements.
When assigning a label element to one of labela or labelb, they should be explicitly cast
to (const char*) if they are not of that type already.
Example Use: Fl_Menu_Bar
\code
Fl_Pixmap *image = new Fl_Pixmap(..); // image for menu item; any Fl_Image based widget
Fl_Menu_Bar *menu = new Fl_Menu_Bar(..); // can be any Fl_Menu_ oriented widget (Fl_Choice, Fl_Menu_Button..)
// Create a menu item
int i = menu->add("File/New", ..);
Fl_Menu_Item *item = (Fl_Menu_Item*)&(menu->menu()[i]);
// Create a multi label, assign it an image + text
Fl_Multi_Label *ml = new Fl_Multi_Label;
// Left side of label is an image
ml->typea = FL_IMAGE_LABEL;
ml->labela = (const char*)image; // any Fl_Image widget: Fl_Pixmap, Fl_PNG_Image, etc..
// Right side of label is label text
ml->typeb = FL_NORMAL_LABEL;
ml->labelb = item->label();
// Assign the multilabel to the menu item
ml->label(item);
\endcode
\see Fl_Label and Fl_Labeltype and examples/howto-menu-with-images.cxx
*/
struct FL_EXPORT Fl_Multi_Label {
/** Holds the "leftmost" of the two elements in the composite label.
Typically this would be assigned either a text string (const char*),
a (Fl_Image*) or a (Fl_Multi_Label*). */
const char* labela;
/** Holds the "rightmost" of the two elements in the composite label.
Typically this would be assigned either a text string (const char*),
a (Fl_Image*) or a (Fl_Multi_Label*). */
const char* labelb;
/** Holds the "type" of labela.
Typically this is set to FL_NORMAL_LABEL for a text label,
FL_IMAGE_LABEL for an image (based on Fl_image) or FL_MULTI_LABEL
if "chaining" multiple Fl_Multi_Label elements together. */
uchar typea;
/** Holds the "type" of labelb.
Typically this is set to FL_NORMAL_LABEL for a text label,
FL_IMAGE_LABEL for an image (based on Fl_image) or FL_MULTI_LABEL
if "chaining" multiple Fl_Multi_Label elements together. */
uchar typeb;
/** This method is used to associate a Fl_Multi_Label with a Fl_Widget. */
void label(Fl_Widget*);
/** This method is used to associate a Fl_Multi_Label with a Fl_Menu_Item. */
void label(Fl_Menu_Item*);
};
#endif