Dynamically resize Fl_Choice widgets

The label and options might vary in size, so it's difficult to pick a
size that always fits. Instead, look at the actual strings and
dynamically resize the widget so everything fits.

vncviewer/OptionsDialog.cxx

@@ -867,6 +867,8 @@ void OptionsDialog::createInputPage(int tx, int ty, int tw, int th)
     fltk_menu_add(cursorTypeChoice, _("Dot"), 0, nullptr, nullptr, 0);
     fltk_menu_add(cursorTypeChoice, _("System"), 0, nullptr, nullptr, 0);
 
+    fltk_adjust_choice(cursorTypeChoice);
+
     ty += CHOICE_HEIGHT + TIGHT_MARGIN;
 
   }
@@ -904,6 +906,8 @@ void OptionsDialog::createInputPage(int tx, int ty, int tw, int th)
     for (int idx = 0; idx < getMenuKeySymbolCount(); idx++)
       fltk_menu_add(menuKeyChoice, getMenuKeySymbols()[idx].name, 0, nullptr, nullptr, 0);
 
+    fltk_adjust_choice(menuKeyChoice);
+
     ty += CHOICE_HEIGHT + TIGHT_MARGIN;
   }
   ty -= TIGHT_MARGIN;

vncviewer/fltk/layout.h

@@ -24,6 +24,7 @@
 #ifndef __FLTK_LAYOUT_H__
 #define __FLTK_LAYOUT_H__
 
+#include <FL/Fl_Choice.H>
 #include <FL/fl_draw.H>
 
 /* Calculates the width of a string as printed by FLTK (pixels) */
@@ -38,6 +39,18 @@ static inline int gui_str_len(const char *str)
     return (int)(len + 0.5f);
 }
 
+/* Adjusts an Fl_Choice so that all options are visible */
+static inline void fltk_adjust_choice(Fl_Choice *choice)
+{
+    int option_len;
+
+    option_len = 0;
+    for (int i = 0; i < choice->size(); i++)
+        option_len = std::max(option_len, gui_str_len(choice->text(i)));
+
+    choice->size(option_len + 30, choice->h());
+}
+
 /**** MARGINS ****/
 
 #define OUTER_MARGIN            15