FLTK Dock: Damage and Redrawing

MyClass::handle(int event) {
  ...
  if (change_to_part1) damage(1);
  if (change_to_part2) damage(2);
  if (change_to_part3) damage(4);
}

MyClass::draw() {
  if (damage() & fltk::DAMAGE_ALL) {
    ... draw frame/box and other static stuff ...
  }
  if (damage() & (fltk::DAMAGE_ALL | 1)) draw_part1();
  if (damage() & (fltk::DAMAGE_ALL | 2)) draw_part2();
  if (damage() & (fltk::DAMAGE_ALL | 4)) draw_part3();
}

Except for DAMAGE_ALL, each widget is allowed to assign any meaning to any of the bits it wants. The enumerations are just to provide suggested meanings.

Function Documentation

uchar Widget::damage ( ) const [inline, inherited]

The 'or' of all the calls to redraw() done since the last draw(). Cleared to zero after draw() is called.

void Widget::draw ( ) [virtual, inherited]

Fltk calls this virtual function to draw the widget, after setting up the graphics (current window, xy translation, etc) so that any drawing functions will go into this widget.

User code should not call this! You probably want to call redraw().

The default version calls draw_box() and draw_label(), thus drawing the box() to fill the widget and putting the label() and image() inside it to fill it, unless the align() flags are set to put it outside.

Information on how to write your own version is here.

Reimplemented in fltk::Divider, fltk::Group, fltk::Window, fltk::DockHolder, fltk::GripperBar, fltk::RegionHolder, fltk::ToolDivider, fltk::ToolWindow, and fltk::WindowHolder.

void Widget::redraw ( uchar flags ) [inherited]

Indicates that draw() should be called, and turns on the given bits in damage(). At least these bits, and possibly others, will still be on when draw() is called.

void Widget::redraw ( ) [inherited]

Same as redraw(DAMAGE_ALL). This bit is used by most widgets to indicate that they should not attempt any incremental update, and should instead completely draw themselves.

void Widget::redraw_highlight ( ) [inherited]

Causes a redraw if highlighting changes.

Calls redraw(DAMAGE_HIGHLIGHT) if this widget has a non-zero highlight_color(). This is designed to be called in response to ENTER and EXIT events and not redraw the widget if the no highlight color is being used.

void Widget::redraw_label ( ) [inherited]

Indicates that the label() should be redrawn. This does nothing if there is no label. If it is an outside label (see align()) then the parent() is told to redraw it. Otherwise redraw() is called.

void Widget::set_damage ( uchar c ) [inline, inherited]

Directly change the value returned by damage(). Note that this replaces the value, it does not turn bits on. Use redraw() to turn bits on.


Functions
uchar	fltk::Widget::damage () const
void	fltk::Widget::set_damage (uchar c)
void	fltk::Widget::redraw ()
void	fltk::Widget::redraw (uchar c)
void	fltk::Widget::redraw_label ()
void	fltk::Widget::redraw_highlight ()
virtual void	fltk::Widget::draw ()

Damage and Redrawing

Functions

Detailed Description

Function Documentation