Mirrors_UI_SDK/fltk
1
0
Fork 0
mirror of https://github.com/fltk/fltk.git synced 2026-05-10 05:27:55 +08:00
Code Issues Actions Packages Projects Releases Wiki Activity

Improve docs and add two new Fl_Menu_Item methods (#875)

Browse Source 
This addresses some issues pointed out by GitHub Issue #875.

Documentation lacked details about Fl_Multi_Label assignment and
correct memory handling.

The new methods
 - Fl_Menu_Item::image_label(const Fl_Image *) and
 - Fl_Menu_Item::multi_label(const Fl_Multi_Label *)
provide a cleaner interface to assign images and Fl_Multi_Label's
to menu items.

examples/howto-menu-with-images.cxx: carify some issues, fix leak,
  and use new Fl_Menu_Item::multi_label(const Fl_Multi_Label *).
This commit is contained in:
Albrecht Schlosser
2023-12-23 18:51:43 +01:00
parent 016c36c917
commit 1d73c0195c
4 changed files with 219 additions and 64 deletions
Download Patch File Download Diff File Expand all files Collapse all files
examples/howto-menu-with-images.cxx
+28 -15
View File
@@ -1,10 +1,8 @@
//
// vim: autoindent tabstop=2 shiftwidth=2 expandtab softtabstop=2 filetype=cpp
//
// How to use Fl_Multi_Label to make menu items with images and labels.
// How to use Fl_Multi_Label to make menu items with images and labels.
//
// Copyright 2017 Greg Ercolano.
// Copyright 1998-2021 by Bill Spitzak and others.
// Copyright 1998-2023 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
@@ -28,6 +26,8 @@
#include <FL/Fl_Pixmap.H>
#include <FL/fl_message.H>
#include <stdlib.h> // free()
// Document icon
static const char *L_document_xpm[] = {
"13 11 3 1",
@@ -120,14 +120,20 @@ int AddItemToMenu(Fl_Menu_ *menu, // menu to add item to
// Right side of label is text
ml->typeb = FL_NORMAL_LABEL;
ml->labelb = item->label();
ml->labelb = item->label(); // transfers "ownership" to ml
// Assign multilabel to item.
// Note: There are two documented ways to achieve this. Both of them
// are supported, but one of them is commented out intentionally.
// There are three documented ways to achieve this. All of them are still
// supported but two of them are deprecated (see docs and comments below).
// The recommended way is to use Fl_Menu_Item::multi_label(Fl_Multi_Label *)
// which was added in FLTK 1.4.0 and sets the correct labeltype().
// All of these statements overwrite the old label (pointer) whose
// ownership has been "transferred" to the Fl_Multi_Label (correct).
// The old label is not released (as documented).
// item->label(FL_MULTI_LABEL, (const char *)ml);
ml->label(item);
// ml->label(item); // deprecated (1.3.x)
// item->label(FL_MULTI_LABEL, (const char *)ml); // deprecated (1.3.x)
item->multi_label(ml); // new since 1.4.0
return i;
}
@@ -151,29 +157,37 @@ void CreateMenuItems(Fl_Menu_* menu) {
// This shows why you need Fl_Multi_Label; the item->label()
// gets clobbered by the item->image() setting.
//
// In the following lines 'menu->add(...)' assigns a duplicated label
// string which must be released prior to assigning an image to the label
// with 'item->image()'.
// This is "not nice" but it prevents memory leaks (see GitHub Issue #875).
int i;
Fl_Menu_Item *item;
i = menu->add("Images/One", 0, Menu_CB, (void*)"One");
item = (Fl_Menu_Item*)&(menu->menu()[i]);
item->image(L_document_pixmap); // note: this clobbers the item's label()
free((void*)item->label());
item->image(L_document_pixmap);
i = menu->add("Images/Two", 0, Menu_CB, (void*)"Two");
item = (Fl_Menu_Item*)&(menu->menu()[i]);
free((void*)item->label());
item->image(L_folder_pixmap);
i = menu->add("Images/Three", 0, Menu_CB, (void*)"Three");
item = (Fl_Menu_Item*)&(menu->menu()[i]);
free((void*)item->label());
item->image(L_redx_pixmap);
}
int main() {
int main(int argc, char **argv) {
Fl_Double_Window *win = new Fl_Double_Window(400, 400, "Menu items with images");
win->tooltip("Right click on window background\nfor popup menu");
// Help message
Fl_Box *box = new Fl_Box(100,100,200,200);
box->copy_label(win->tooltip());
box->label(win->tooltip()); // no need to copy_label() because it's static
box->align(FL_ALIGN_CENTER|FL_ALIGN_INSIDE);
// Menu bar
@@ -192,12 +206,11 @@ int main() {
// TODO: Show complex labels with Fl_Multi_Label. From docs:
//
// "More complex labels might be constructed by setting labelb as another
// "More complex labels can be constructed by setting labelb as another
// Fl_Multi_Label and thus chaining up a series of label elements."
//
win->end();
win->resizable(win);
win->show();
win->show(argc, argv);
return Fl::run();
}