mirrors/fltk
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Improve docs about subclassing

Browse Source 
- fix syntax errors in example code, e.g.: children_ is private
- use FLTK coding style
- improve alignment
This commit is contained in:
Albrecht Schlosser 2024-10-24 17:59:18 +02:00
parent eb545c981b
commit f9f89be7d7
1 changed files with 41 additions and 39 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

54
documentation/src/subclassing.dox
View File

@ -47,8 +47,8 @@ pass the same arguments:
\code \code
MyClass::MyClass(int x, int y, int w, int h, const char *label) MyClass::MyClass(int x, int y, int w, int h, const char *label)
: Fl_Widget(x, y, w, h, label) { : Fl_Widget(x, y, w, h, label) {
// do initialization stuff... // do initialization stuff...
} }
\endcode \endcode
@ -57,19 +57,19 @@ Fl_Widget's protected constructor sets \p x(), \p y(),
and initializes the other instance variables to: and initializes the other instance variables to:
\code \code
type(0); type(0);
box(FL_NO_BOX); box(FL_NO_BOX);
color(FL_BACKGROUND_COLOR); color(FL_BACKGROUND_COLOR);
selection_color(FL_BACKGROUND_COLOR); selection_color(FL_BACKGROUND_COLOR);
labeltype(FL_NORMAL_LABEL); labeltype(FL_NORMAL_LABEL);
labelstyle(FL_NORMAL_STYLE); labelstyle(FL_NORMAL_STYLE);
labelsize(FL_NORMAL_SIZE); labelsize(FL_NORMAL_SIZE);
labelcolor(FL_FOREGROUND_COLOR); labelcolor(FL_FOREGROUND_COLOR);
align(FL_ALIGN_CENTER); align(FL_ALIGN_CENTER);
callback(default_callback,0); callback(default_callback,0);
flags(ACTIVE|VISIBLE); flags(ACTIVE|VISIBLE);
image(0); image(0);
deimage(0); deimage(0);
\endcode \endcode
\section subclassing_protected Protected Methods of Fl_Widget \section subclassing_protected Protected Methods of Fl_Widget
@ -118,22 +118,22 @@ see what parts of your widget need redrawing.</I> The \p handle()
method can then set individual damage bits to limit the amount of drawing method can then set individual damage bits to limit the amount of drawing
that needs to be done: that needs to be done:
\code \code
MyClass::handle(int event) { int MyClass::handle(int event) {
... // ...
if (change_to_part1) damage(1); if (change_to_part1) damage(1);
if (change_to_part2) damage(2); if (change_to_part2) damage(2);
if (change_to_part3) damage(4); if (change_to_part3) damage(4);
} }
MyClass::draw() { void MyClass::draw() {
if (damage() & FL_DAMAGE_ALL) { if (damage() & FL_DAMAGE_ALL) {
... draw frame/box and other static stuff ... // ... draw frame/box and other static stuff ...
} }
if (damage() & (FL_DAMAGE_ALL | 1)) draw_part1(); if (damage() & (FL_DAMAGE_ALL | 1)) draw_part1();
if (damage() & (FL_DAMAGE_ALL | 2)) draw_part2(); if (damage() & (FL_DAMAGE_ALL | 2)) draw_part2();
if (damage() & (FL_DAMAGE_ALL | 4)) draw_part3(); if (damage() & (FL_DAMAGE_ALL | 4)) draw_part3();
} }
\endcode \endcode
\todo Clarify Fl_Window::damage(uchar) handling - seems confused/wrong? \todo Clarify Fl_Window::damage(uchar) handling - seems confused/wrong?
@ -259,7 +259,7 @@ a pushbutton and also accepts the keystroke \p 'x' to cause the callback:
\code \code
int MyClass::handle(int event) { int MyClass::handle(int event) {
switch(event) { switch (event) {
case FL_PUSH: case FL_PUSH:
highlight = 1; highlight = 1;
redraw(); redraw();
@ -416,14 +416,16 @@ that a child needs to be drawn. It is fastest if you avoid
drawing anything else in this case: drawing anything else in this case:
\code \code
int MyClass::draw() { void MyClass::draw() {
Fl_Widget *const*a = array(); Fl_Widget *const*a = array();
if (damage() == FL_DAMAGE_CHILD) { // only redraw some children if (damage() == FL_DAMAGE_CHILD) { // only redraw some children
for (int i = children(); i --; a ++) update_child(**a); for (int i = children(); i--; a++) {
update_child(**a);
}
} else { // total redraw } else { // total redraw
... draw background graphics ... // ... draw background graphics ...
// now draw all the children atop the background: // now draw all the children atop the background:
for (int i = children_; i --; a ++) { for (int i = children(); i--; a++) {
draw_child(**a); draw_child(**a);
draw_outside_label(**a); // you may not need to do this draw_outside_label(**a); // you may not need to do this
} }