The Fl_Tabs widget is the "file card tabs" interface that allows you to put lots and lots of buttons and switches in a panel, as popularized by many toolkits. More...
#include <Fl_Tabs.H>
Public Member Functions | |
void | client_area (int &rx, int &ry, int &rw, int &rh, int tabh=0) |
Returns the position and size available to be used by its children. | |
Fl_Tabs (int, int, int, int, const char *=0) | |
Creates a new Fl_Tabs widget using the given position, size, and label string. | |
int | handle (int) |
Handles the specified event. | |
int | push (Fl_Widget *) |
This is called by the tab widget's handle() method to set the tab group widget the user last FL_PUSH'ed on. | |
Fl_Widget * | push () const |
Returns the tab group for the tab the user has currently down-clicked on and remains over until FL_RELEASE. | |
int | value (Fl_Widget *) |
Sets the widget to become the current visible widget/tab. | |
Fl_Widget * | value () |
Gets the currently visible widget/tab. | |
Fl_Widget * | which (int event_x, int event_y) |
Return the widget of the tab the user clicked on at event_x / event_y . | |
Protected Member Functions | |
void | draw () |
Draws the widget. | |
void | redraw_tabs () |
The Fl_Tabs widget is the "file card tabs" interface that allows you to put lots and lots of buttons and switches in a panel, as popularized by many toolkits.
Clicking the tab makes a child visible() by calling show() on it, and all other children are made invisible by calling hide() on them. Usually the children are Fl_Group widgets containing several widgets themselves.
Each child makes a card, and its label() is printed on the card tab, including the label font and style. The selection color of that child is used to color the tab, while the color of the child determines the background color of the pane.
The size of the tabs is controlled by the bounding box of the children (there should be some space between the children and the edge of the Fl_Tabs), and the tabs may be placed "inverted" on the bottom - this is determined by which gap is larger. It is easiest to lay this out in fluid, using the fluid browser to select each child group and resize them until the tabs look the way you want them to.
The background area behind and to the right of the tabs is "transparent", exposing the background detail of the parent. The value of Fl_Tabs::box() does not affect this area. So if Fl_Tabs is resized by itself without the parent, force the appropriate parent (visible behind the tabs) to redraw() to prevent artifacts.
See "Resizing Caveats" below on how to keep tab heights constant. See "Callback's Use Of when()" on how to control the details of how clicks invoke the callback().
A typical use of the Fl_Tabs widget:
Default Appearance
The appearance of each "tab" is taken from the label() and color() of the child group corresponding to that "tab" and panel. Where the "tabs" appear depends on the position and size of the child groups that make up the panels within the Fl_Tab, i.e. whether there is more space above or below them. The height of the "tabs" depends on how much free space is available.
Fl_Tabs Default Appearance
Highlighting The Selected Tab
The selected "tab" can be highlighted further by setting the selection_color() of the Fl_Tab itself, e.g.
.. tabs = new Fl_Tabs(..); tabs->selection_color(FL_DARK3); ..
The result of the above looks like:
Highlighting the selected tab
Uniform Tab and Panel Appearance
In order to have uniform tab and panel appearance, not only must the color() and selection_color() for each child group be set, but also the selection_color() of the Fl_Tab itself any time a new "tab" is selected. This can be achieved within the Fl_Tab callback, e.g.
void MyTabCallback(Fl_Widget *w, void*) { Fl_Tabs *tabs = (Fl_Tabs*)w; // When tab changed, make sure it has same color as its group tabs->selection_color( (tab->value())->color() ); } .. int main(..) { // Define tabs widget tabs = new Fl_Tabs(..); tabs->callback(MyTabCallback); // Create three tabs each colored differently grp1 = new Fl_Group(.. "One"); grp1->color(9); grp1->selection_color(9); grp1->end(); grp2 = new Fl_Group(.. "Two"); grp2->color(10); grp2->selection_color(10); grp2->end(); grp3 = new Fl_Group(.. "Three"); grp3->color(14); grp3->selection_color(14); grp3->end(); .. // Make sure default tab has same color as its group tabs->selection_color( (tab->value())->color() ); .. return Fl::run(); }
The result of the above looks like:
Fl_Tabs with uniform colors
Resizing Caveats
When Fl_Tabs is resized vertically, the default behavior scales the tab's height as well as its children. To keep the tab height constant during resizing, set the tab widget's resizable() to one of the tab's child groups, i.e.
As of FLTK 1.3.3, Fl_Tabs() supports the following flags for when():
Notes:
Fl_Tabs::Fl_Tabs | ( | int | X, | |
int | Y, | |||
int | W, | |||
int | H, | |||
const char * | l = 0 | |||
) |
Creates a new Fl_Tabs widget using the given position, size, and label string.
The default boxtype is FL_THIN_UP_BOX.
Use add(Fl_Widget*) to add each child, which are usually Fl_Group widgets. The children should be sized to stay away from the top or bottom edge of the Fl_Tabs widget, which is where the tabs will be drawn.
All children of Fl_Tabs should have the same size and exactly fit on top of each other. They should only leave space above or below where the tabs will go, but not on the sides. If the first child of Fl_Tabs is set to "resizable()", the riders will not resize when the tabs are resized.
The destructor also deletes all the children. This allows a whole tree to be deleted at once, without having to keep a pointer to all the children in the user code. A kludge has been done so the Fl_Tabs and all of its children can be automatic (local) variables, but you must declare the Fl_Tabs widget first so that it is destroyed last.
void Fl_Tabs::client_area | ( | int & | rx, | |
int & | ry, | |||
int & | rw, | |||
int & | rh, | |||
int | tabh = 0 | |||
) |
Returns the position and size available to be used by its children.
If there isn't any child yet the tabh
parameter will be used to calculate the return values. This assumes that the children's labelsize is the same as the Fl_Tabs' labelsize and adds a small border.
If there are already children, the values of child(0) are returned, and tabh
is ignored.
tabh
can be one of
tabh
value, tabs on top (height = tabh) tabh
value, tabs on bottom (height = -tabh)[in] | tabh | position and optional height of tabs (see above) |
[out] | rx,ry,rw,rh | (x,y,w,h) of client area for children |
void Fl_Tabs::draw | ( | ) | [protected, virtual] |
Draws the widget.
Never call this function directly. FLTK will schedule redrawing whenever needed. If your widget must be redrawn as soon as possible, call redraw() instead.
Override this function to draw your own widgets.
If you ever need to call another widget's draw method from within your own draw() method, e.g. for an embedded scrollbar, you can do it (because draw() is virtual) like this:
Fl_Widget *s = &scroll; // scroll is an embedded Fl_Scrollbar s->draw(); // calls Fl_Scrollbar::draw()
Reimplemented from Fl_Group.
int Fl_Tabs::handle | ( | int | event | ) | [virtual] |
Handles the specified event.
You normally don't call this method directly, but instead let FLTK do it when the user interacts with the widget.
When implemented in a widget, this function must return 0 if the widget does not use the event or 1 otherwise.
Most of the time, you want to call the inherited handle() method in your overridden method so that you don't short-circuit events that you don't handle. In this last case you should return the callee retval.
[in] | event | the kind of event received |
0 | if the event was not used or understood | |
1 | if the event was used and can be deleted |
Reimplemented from Fl_Group.
int Fl_Tabs::push | ( | Fl_Widget * | o | ) |
This is called by the tab widget's handle() method to set the tab group widget the user last FL_PUSH'ed on.
Set back to zero on FL_RELEASE.
As of this writing, the value is mainly used by draw_tab() to determine whether or not to draw a 'down' box for the tab when it's clicked, and to turn it off if the user drags off it.
Fl_Widget* Fl_Tabs::push | ( | ) | const [inline] |
Returns the tab group for the tab the user has currently down-clicked on and remains over until FL_RELEASE.
Otherwise, returns NULL.
While the user is down-clicked on a tab, the return value is the tab group for that tab. But as soon as the user releases, or drags off the tab with the button still down, the return value will be NULL.
int Fl_Tabs::value | ( | Fl_Widget * | newvalue | ) |
Sets the widget to become the current visible widget/tab.
Setting the value hides all other children, and makes this one visible, if it is really a child.
Fl_Widget * Fl_Tabs::value | ( | ) |
Fl_Widget * Fl_Tabs::which | ( | int | event_x, | |
int | event_y | |||
) |
Return the widget of the tab the user clicked on at event_x
/ event_y
.
This is used for event handling (clicks) and by fluid to pick tabs.