Version 5.0 The LEDA User Manual

in this section add panel items or buttons to the panel section of W . Note that they have
to be called before the window is displayed the first time.
In general, a panel item consists of a string label and an associated variable of a certain
type (int, bool, string, double, color). The value of this variable can be manipulated
through the item. Each button has a label (displayed on the button) and an associated
number. The number of a button is either defined by the user or is the rank of the button
in the list of all buttons. If a button is pressed (i.e. selected by a mouse click) during a
read mouse operation its number is returned.
Action functions can be associated with buttons and some items (e.g. slider items) whenever
a button with an associated action function is pressed this function is called with the
number of the button as actual parameter. Action functions of items are called whenever
the value of the corresponding variable is changed with the new value as actual parameter.
All action functions must have the type void func(int).
Another way to define a button is to associate another window with it. In this case the
button will have a menu sign and as soon as it is pressed the attached window will open.
This method can be used to implement pop-up menues. The return value of the current
read mouse operation will be the number associated with the button in the menu.
3.9.1 General Settings
void W.set panel bg color(color c)
void W.buttons per line(int n)
void W.set button space(int s)
void W.set item height(int h)
void W.set item width(int w)
void W.set bitmap colors(int c 0 , int c 1 )
3.9.2 Simple Panel Items
sets the background color of the panel area to c.
defines the maximal number n of buttons per line.
sets the space between to adjacent buttons to s
pixels.
sets the vertical size of all items to h pixels.
sets the horizontal size of all slider and string items
to w pixels.
sets the unpressed/pressed colors used for drawing
the pixels in bitmap buttons to c 0 and c 1 .
panel item W.text item(string s) adds a text item s to W .