Tree widget item. More...
#include <Fl_Tree_Item.H>
Public Member Functions | |
void | activate (int val=1) |
Change the item's activation state to the optionally specified 'val'. | |
Fl_Tree_Item * | add (const Fl_Tree_Prefs &prefs, char **arr) |
Descend into the path specified by 'arr' , and add a new child there. | |
Fl_Tree_Item * | add (const Fl_Tree_Prefs &prefs, char **arr, Fl_Tree_Item *newitem) |
Descend into path specified by 'arr' and add 'newitem' there. | |
Fl_Tree_Item * | add (const Fl_Tree_Prefs &prefs, const char *new_label) |
Add a new child to this item with the name 'new_label' and defaults from 'prefs' . | |
Fl_Tree_Item * | add (const Fl_Tree_Prefs &prefs, const char *new_label, Fl_Tree_Item *newitem) |
Add 'item' as immediate child with 'new_label' and defaults from 'prefs' . | |
const Fl_Tree_Item * | child (int t) const |
Return the const child item for the given 'index'. | |
Fl_Tree_Item * | child (int index) |
Return the child item for the given 'index'. | |
int | children () const |
Return the number of children this item has. | |
void | clear_children () |
Clear all the children for this item. | |
void | close () |
Close this item and all its children. | |
void | deactivate () |
Deactivate the item; the callback() won't be invoked when clicked. | |
Fl_Tree_Item * | deparent (int index) |
Deparent child at index position 'pos' . | |
int | depth () const |
Returns how many levels deep this item is in the hierarchy. | |
void | deselect () |
Disable the item's selection state. | |
int | deselect_all () |
Deselect item and all its children. | |
void | draw (int X, int &Y, int W, Fl_Widget *tree, Fl_Tree_Item *itemfocus, const Fl_Tree_Prefs &prefs, int lastchild=1) |
Draw this item and its children. | |
int | event_on_collapse_icon (const Fl_Tree_Prefs &prefs) const |
Was the event on the 'collapse' button of this item? | |
int | event_on_label (const Fl_Tree_Prefs &prefs) const |
Was event on the label() of this item? | |
int | find_child (Fl_Tree_Item *item) |
Find the index number for the specified 'item' in the current item's list of children. | |
int | find_child (const char *name) |
Return the index of the immediate child of this item that has the label 'name' . | |
Fl_Tree_Item * | find_child_item (char **arr) |
Non-const version of Fl_Tree_Item::find_child_item(char **arr) const. | |
const Fl_Tree_Item * | find_child_item (char **arr) const |
Find child item by descending array 'arr' of names. | |
Fl_Tree_Item * | find_child_item (const char *name) |
Non-const version of Fl_Tree_Item::find_child_item(const char *name) const. | |
const Fl_Tree_Item * | find_child_item (const char *name) const |
Return the /immediate/ child of current item that has the label 'name' . | |
Fl_Tree_Item * | find_clicked (const Fl_Tree_Prefs &prefs) |
Non-const version of Fl_Tree_Item::find_clicked(const Fl_Tree_Prefs&) const. | |
const Fl_Tree_Item * | find_clicked (const Fl_Tree_Prefs &prefs) const |
Set the usericon to draw when the item is deactivated. | |
Fl_Tree_Item * | find_item (char **arr) |
Non-const version of Fl_Tree_Item::find_item(char **names) const. | |
const Fl_Tree_Item * | find_item (char **arr) const |
Find item by descending array of 'names' . | |
Fl_Tree_Item (const Fl_Tree_Item *o) | |
Copy constructor. | |
Fl_Tree_Item (const Fl_Tree_Prefs &prefs) | |
Constructor. | |
int | h () const |
The item's height. | |
int | has_children () const |
See if this item has children. | |
Fl_Tree_Item * | insert (const Fl_Tree_Prefs &prefs, const char *new_label, int pos=0) |
Insert a new item named 'new_label' into current item's children at a specified position 'pos' . | |
Fl_Tree_Item * | insert_above (const Fl_Tree_Prefs &prefs, const char *new_label) |
Insert a new item named 'new_label' above this item. | |
char | is_activated () const |
See if the item is activated. | |
char | is_active () const |
See if the item is activated. Alias for is_activated(). | |
int | is_close () const |
See if the item is 'closed'. | |
int | is_open () const |
See if the item is 'open'. | |
int | is_root () const |
Is this item the root of the tree? | |
char | is_selected () const |
See if the item is selected. | |
int | is_visible () const |
See if the item is visible. | |
const char * | label () const |
Return the label. | |
void | label (const char *val) |
Set the label to 'name' . | |
int | label_h () const |
The item's label height. | |
int | label_w () const |
The item's maximum label width to right edge of Fl_Tree's inner width within scrollbars. | |
int | label_x () const |
The item's label x position relative to the window. | |
int | label_y () const |
The item's label y position relative to the window. | |
Fl_Color | labelbgcolor () const |
Return item's label background text color. | |
void | labelbgcolor (Fl_Color val) |
Set item's label background color. | |
Fl_Color | labelcolor () const |
Return item's label text color. Alias for labelfgcolor() const). | |
void | labelcolor (Fl_Color val) |
Set item's label text color. Alias for labelfgcolor(Fl_Color)). | |
Fl_Color | labelfgcolor () const |
Return item's label foreground text color. | |
void | labelfgcolor (Fl_Color val) |
Set item's label foreground text color. | |
Fl_Font | labelfont () const |
Get item's label font face. | |
void | labelfont (Fl_Font val) |
Set item's label font face. | |
Fl_Fontsize | labelsize () const |
Get item's label font size. | |
void | labelsize (Fl_Fontsize val) |
Set item's label font size. | |
int | move (Fl_Tree_Item *item, int op=0, int pos=0) |
Move the current item above/below/into the specified 'item', where 'op' determines the type of move:. | |
int | move (int to, int from) |
Move the item 'from' to sibling position of 'to'. | |
int | move_above (Fl_Tree_Item *item) |
Move the current item above the specified 'item'. | |
int | move_below (Fl_Tree_Item *item) |
Move the current item below the specified 'item'. | |
int | move_into (Fl_Tree_Item *item, int pos=0) |
Parent the current item as a child of the specified 'item' . | |
Fl_Tree_Item * | next () |
Return the next item in the tree. | |
Fl_Tree_Item * | next_displayed (Fl_Tree_Prefs &prefs) |
Same as next_visible(). | |
Fl_Tree_Item * | next_sibling () |
Return this item's next sibling. | |
Fl_Tree_Item * | next_visible (Fl_Tree_Prefs &prefs) |
Return the next open(), visible() item. | |
void | open () |
Open this item and all its children. | |
void | open_toggle () |
Toggle the item's open/closed state. | |
void | parent (Fl_Tree_Item *val) |
Set the parent for this item. | |
const Fl_Tree_Item * | parent () const |
Return the const parent for this item. Returns NULL if we are the root. | |
Fl_Tree_Item * | parent () |
Return the parent for this item. Returns NULL if we are the root. | |
Fl_Tree_Item * | prev () |
Return the previous item in the tree. | |
Fl_Tree_Item * | prev_displayed (Fl_Tree_Prefs &prefs) |
Same as prev_visible(). | |
Fl_Tree_Item * | prev_sibling () |
Return this item's previous sibling. | |
Fl_Tree_Item * | prev_visible (Fl_Tree_Prefs &prefs) |
Return the previous open(), visible() item. | |
int | remove_child (const char *new_label) |
Remove immediate child (and its children) by its label 'name' . | |
int | remove_child (Fl_Tree_Item *item) |
Remove 'item' from the current item's children. | |
int | reparent (Fl_Tree_Item *newchild, int index) |
Reparent specified item as a child of ourself at position 'pos' . | |
void | select (int val=1) |
Change the item's selection state to the optionally specified 'val'. | |
int | select_all () |
Select item and all its children. | |
void | select_toggle () |
Toggle the item's selection state. | |
void | show_self (const char *indent="") const |
Print the tree as 'ascii art' to stdout. | |
int | swap_children (Fl_Tree_Item *a, Fl_Tree_Item *b) |
Swap two of our immediate children, given item pointers. | |
void | swap_children (int ax, int bx) |
Swap two of our children, given two child index values 'ax' and 'bx' . | |
void | update_prev_next (int index) |
Update our _prev_sibling and _next_sibling pointers to point to neighbors given index as being our current position in the parent's item array. | |
void * | user_data () const |
Retrieve the user-data value that has been assigned to the item. | |
void | user_data (void *data) |
Set a user-data value for the item. | |
Fl_Image * | usericon () const |
Get the item's user icon as an Fl_Image. Returns '0' if disabled. | |
void | usericon (Fl_Image *val) |
Set the item's user icon to an Fl_Image. | |
int | visible () const |
See if the item is visible. Alias for is_visible(). | |
int | visible_r () const |
See if item and all its parents are open() and visible(). | |
int | w () const |
The entire item's width to right edge of Fl_Tree's inner width within scrollbars. | |
Fl_Widget * | widget () const |
Return FLTK widget assigned to this item. | |
void | widget (Fl_Widget *val) |
Assign an FLTK widget to this item. | |
int | x () const |
The item's x position relative to the window. | |
int | y () const |
The item's y position relative to the window. | |
Protected Member Functions | |
void | _Init (const Fl_Tree_Prefs &prefs, Fl_Tree *tree) |
int | calc_item_height (const Fl_Tree_Prefs &prefs) const |
Return the item's 'visible' height. | |
void | draw_horizontal_connector (int x1, int x2, int y, const Fl_Tree_Prefs &prefs) |
Internal: Horizontal connector line based on preference settings. | |
void | draw_vertical_connector (int x, int y1, int y2, const Fl_Tree_Prefs &prefs) |
Internal: Vertical connector line based on preference settings. | |
void | hide_widgets () |
Internal: Hide the FLTK widget() for this item and all children. | |
int | is_flag (unsigned short flag) const |
See if flag set. Returns 0 or 1. | |
void | recalc_tree () |
Call this when our geometry is changed. | |
void | set_flag (unsigned short flag, int val) |
Set a flag to an on or off value. val is 0 or 1. | |
void | show_widgets () |
Internal: Show the FLTK widget() for this item and all children. |
Tree widget item.
This class is a single tree item, and manages all of the item's attributes. Fl_Tree_Item is used by Fl_Tree, which is comprised of many instances of Fl_Tree_Item.
Fl_Tree_Item is hierarchical; it dynamically manages an Fl_Tree_Item_Array of children that are themselves instances of Fl_Tree_Item. Each item can have zero or more children. When an item has children, close() and open() can be used to hide or show them.
Items have their own attributes; font size, face, color. Items maintain their own hierarchy of children.
When you make changes to items, you'll need to tell the tree to redraw() for the changes to show up.
New 1.3.3 ABI feature: You can define custom items by either adding a custom widget to the item with Fl_Tree_Item::widget(), or override the draw_item_content() method if you want to just redefine how the label is drawn.
The following shows the Fl_Tree_Item's dimensions, useful when overriding the draw_item_content() method:
Fl_Tree_Item's internal dimensions.
Fl_Tree_Item::Fl_Tree_Item | ( | const Fl_Tree_Prefs & | prefs | ) |
Constructor.
Makes a new instance of Fl_Tree_Item using defaults from 'prefs'
.
void Fl_Tree_Item::activate | ( | int | val = 1 |
) | [inline] |
Change the item's activation state to the optionally specified 'val'.
When deactivated, the item will be 'grayed out'; the callback() won't be invoked if the user clicks on the label. If a widget() is associated with the item, its activation state will be changed as well.
If 'val' is not specified, the item will be activated.
Fl_Tree_Item * Fl_Tree_Item::add | ( | const Fl_Tree_Prefs & | prefs, | |
char ** | arr | |||
) |
Descend into the path specified by 'arr'
, and add a new child there.
Should be used only by Fl_Tree's internals. Adds the item based on the value of prefs.sortorder().
Fl_Tree_Item * Fl_Tree_Item::add | ( | const Fl_Tree_Prefs & | prefs, | |
char ** | arr, | |||
Fl_Tree_Item * | newitem | |||
) |
Descend into path specified by 'arr'
and add 'newitem'
there.
Should be used only by Fl_Tree's internals. If item is NULL, a new item is created. Adds the item based on the value of prefs.sortorder().
Fl_Tree_Item * Fl_Tree_Item::add | ( | const Fl_Tree_Prefs & | prefs, | |
const char * | new_label | |||
) |
Add a new child to this item with the name 'new_label'
and defaults from 'prefs'
.
An internally managed copy is made of the label string. Adds the item based on the value of prefs.sortorder().
Fl_Tree_Item * Fl_Tree_Item::add | ( | const Fl_Tree_Prefs & | prefs, | |
const char * | new_label, | |||
Fl_Tree_Item * | item | |||
) |
Add 'item'
as immediate child with 'new_label'
and defaults from 'prefs'
.
If 'item'
is NULL, a new item is created. An internally managed copy is made of the label string. Adds the item based on the value of prefs.sortorder().
int Fl_Tree_Item::calc_item_height | ( | const Fl_Tree_Prefs & | prefs | ) | const [protected] |
Return the item's 'visible' height.
Takes into account the item's:
const Fl_Tree_Item * Fl_Tree_Item::child | ( | int | t | ) | const |
Return the const child item for the given 'index'.
Return const child item for the specified 'index'.
void Fl_Tree_Item::deactivate | ( | ) | [inline] |
Deactivate the item; the callback() won't be invoked when clicked.
Same as activate(0)
Fl_Tree_Item * Fl_Tree_Item::deparent | ( | int | pos | ) |
Deparent child at index position 'pos'
.
This creates an "orphaned" item that is still allocated, but has no parent or siblings. Normally the caller would want to immediately reparent the orphan elsewhere.
A successfully orphaned item will have its parent() and prev_sibling()/next_sibling() set to NULL.
int Fl_Tree_Item::depth | ( | ) | const |
Returns how many levels deep this item is in the hierarchy.
For instance; root has a depth of zero, and its immediate children would have a depth of 1, and so on. Use e.g. for determining the horizontal indent of this item during drawing.
int Fl_Tree_Item::deselect_all | ( | ) | [inline] |
Deselect item and all its children.
Returns count of how many items were in the 'selected' state, ie. how many items were "changed".
void Fl_Tree_Item::draw | ( | int | X, | |
int & | Y, | |||
int | W, | |||
Fl_Widget * | tree, | |||
Fl_Tree_Item * | itemfocus, | |||
const Fl_Tree_Prefs & | prefs, | |||
int | lastchild = 1 | |||
) |
Draw this item and its children.
[in] | X | Horizontal position for item being drawn |
[in,out] | Y | Vertical position for item being drawn, returns new position for next item |
[in] | W | Recommended width of item |
[in] | tree | The parent tree |
[in] | itemfocus | The tree's current focus item (if any) |
[in] | prefs | The tree's preferences |
[in] | lastchild | Is this item the last child in a subtree? |
void Fl_Tree_Item::draw_horizontal_connector | ( | int | x1, | |
int | x2, | |||
int | y, | |||
const Fl_Tree_Prefs & | prefs | |||
) | [protected] |
Internal: Horizontal connector line based on preference settings.
[in] | x1 | The left hand X position of the horizontal connector |
[in] | x2 | The right hand X position of the horizontal connector |
[in] | y | The vertical position of the horizontal connector |
[in] | prefs | The Fl_Tree prefs |
void Fl_Tree_Item::draw_vertical_connector | ( | int | x, | |
int | y1, | |||
int | y2, | |||
const Fl_Tree_Prefs & | prefs | |||
) | [protected] |
Internal: Vertical connector line based on preference settings.
[in] | x | The x position of the vertical connector |
[in] | y1 | The top of the vertical connector |
[in] | y2 | The bottom of the vertical connector |
[in] | prefs | The Fl_Tree prefs |
int Fl_Tree_Item::find_child | ( | Fl_Tree_Item * | item | ) |
Find the index number for the specified 'item'
in the current item's list of children.
int Fl_Tree_Item::find_child | ( | const char * | name | ) |
Return the index of the immediate child of this item that has the label 'name'
.
const Fl_Tree_Item * Fl_Tree_Item::find_child_item | ( | char ** | arr | ) | const |
Find child item by descending array 'arr'
of names.
Does not include self in search. Only Fl_Tree should need this method.
const Fl_Tree_Item * Fl_Tree_Item::find_child_item | ( | const char * | name | ) | const |
Return the /immediate/ child of current item that has the label 'name'
.
const Fl_Tree_Item * Fl_Tree_Item::find_clicked | ( | const Fl_Tree_Prefs & | prefs | ) | const |
Set the usericon to draw when the item is deactivated.
Find the item that the last event was over.
Use '0' to disable. No internal copy is made; caller must manage icon's memory.
To create a typical 'grayed out' version of your usericon image, you can do the following:
// Create tree + usericon for items Fl_Tree *tree = new Fl_Tree(..); Fl_Image *usr_icon = new Fl_Pixmap(..); // your usericon Fl_Image *de_icon = usr_icon->copy(); // make a copy, and.. de_icon->inactive(); // make it 'grayed out' ... for ( .. ) { // item loop.. item = tree->add("..."); // create new item item->usericon(usr_icon); // assign usericon to items item->userdeicon(de_icon); // assign userdeicon to items .. }
In the above example, the app should 'delete' the two icons when they're no longer needed (e.g. after the tree is destroyed)
[in] | prefs | The parent tree's Fl_Tree_Prefs |
const Fl_Tree_Item * Fl_Tree_Item::find_item | ( | char ** | names | ) | const |
Find item by descending array of 'names'
.
Includes self in search. Only Fl_Tree should need this method. Use Fl_Tree::find_item() instead.
void Fl_Tree_Item::hide_widgets | ( | ) | [protected] |
Fl_Tree_Item * Fl_Tree_Item::insert | ( | const Fl_Tree_Prefs & | prefs, | |
const char * | new_label, | |||
int | pos = 0 | |||
) |
Insert a new item named 'new_label'
into current item's children at a specified position 'pos'
.
If pos
is out of range the new item is
pos
< 0 orpos
> item->children().Fl_Tree_Item * Fl_Tree_Item::insert_above | ( | const Fl_Tree_Prefs & | prefs, | |
const char * | new_label | |||
) |
Insert a new item named 'new_label'
above this item.
void Fl_Tree_Item::label | ( | const char * | name | ) |
Set the label to 'name'
.
Makes and manages an internal copy of 'name'
.
int Fl_Tree_Item::label_h | ( | ) | const [inline] |
The item's label height.
int Fl_Tree_Item::label_w | ( | ) | const [inline] |
The item's maximum label width to right edge of Fl_Tree's inner width within scrollbars.
int Fl_Tree_Item::label_x | ( | ) | const [inline] |
The item's label x position relative to the window.
int Fl_Tree_Item::label_y | ( | ) | const [inline] |
The item's label y position relative to the window.
Fl_Color Fl_Tree_Item::labelbgcolor | ( | ) | const [inline] |
Return item's label background text color.
If the color is 0xffffffff, the default behavior is the parent tree's bg color will be used. (An overloaded draw_item_content() can override this behavior.)
void Fl_Tree_Item::labelbgcolor | ( | Fl_Color | val | ) | [inline] |
Set item's label background color.
A special case is made for color 0xffffffff which uses the parent tree's bg color.
int Fl_Tree_Item::move | ( | Fl_Tree_Item * | item, | |
int | op = 0 , |
|||
int | pos = 0 | |||
) |
Move the current item above/below/into the specified 'item', where 'op'
determines the type of move:.
'item'
('pos'
ignored)'item'
('pos'
ignored)'item'
as a child (at optional position 'pos'
)'pos'
int Fl_Tree_Item::move | ( | int | to, | |
int | from | |||
) |
Move the item 'from' to sibling position of 'to'.
'to'
or 'from'
out of range).int Fl_Tree_Item::move_above | ( | Fl_Tree_Item * | item | ) |
Move the current item above the specified 'item'.
This is the equivalent of calling move(item,0,0).
int Fl_Tree_Item::move_below | ( | Fl_Tree_Item * | item | ) |
Move the current item below the specified 'item'.
This is the equivalent of calling move(item,1,0).
int Fl_Tree_Item::move_into | ( | Fl_Tree_Item * | item, | |
int | pos = 0 | |||
) |
Parent the current item as a child of the specified 'item'
.
This is the equivalent of calling move(item,2,pos).
Fl_Tree_Item * Fl_Tree_Item::next | ( | ) |
Return the next item in the tree.
This method can be used to walk the tree forward. For an example of how to use this method, see Fl_Tree::first().
Fl_Tree_Item * Fl_Tree_Item::next_displayed | ( | Fl_Tree_Prefs & | prefs | ) |
Same as next_visible().
Fl_Tree_Item * Fl_Tree_Item::next_sibling | ( | ) |
Return this item's next sibling.
Moves to the next item below us at the same level (sibling). Use this to move down the tree without changing depth(). effectively skipping over this item's children/descendents.
Fl_Tree_Item * Fl_Tree_Item::next_visible | ( | Fl_Tree_Prefs & | prefs | ) |
void Fl_Tree_Item::parent | ( | Fl_Tree_Item * | val | ) | [inline] |
Set the parent for this item.
Should only be used by Fl_Tree's internals.
Fl_Tree_Item * Fl_Tree_Item::prev | ( | ) |
Return the previous item in the tree.
This method can be used to walk the tree backwards. For an example of how to use this method, see Fl_Tree::last().
Fl_Tree_Item * Fl_Tree_Item::prev_displayed | ( | Fl_Tree_Prefs & | prefs | ) |
Same as prev_visible().
Fl_Tree_Item * Fl_Tree_Item::prev_sibling | ( | ) |
Return this item's previous sibling.
Moves to the previous item above us at the same level (sibling). Use this to move up the tree without changing depth().
Fl_Tree_Item * Fl_Tree_Item::prev_visible | ( | Fl_Tree_Prefs & | prefs | ) |
void Fl_Tree_Item::recalc_tree | ( | ) | [protected] |
Call this when our geometry is changed.
(Font size, label contents, etc) Schedules tree to recalculate itself, as changes to us may affect tree widget's scrollbar visibility and tab sizes.
int Fl_Tree_Item::remove_child | ( | const char * | name | ) |
Remove immediate child (and its children) by its label 'name'
.
If more than one item matches 'name'
, only the first matching item is removed.
[in] | name | The label name of the immediate child to remove |
int Fl_Tree_Item::remove_child | ( | Fl_Tree_Item * | item | ) |
Remove 'item'
from the current item's children.
int Fl_Tree_Item::reparent | ( | Fl_Tree_Item * | newchild, | |
int | pos | |||
) |
Reparent specified item as a child of ourself at position 'pos'
.
Typically 'newchild' was recently orphaned with deparent().
'pos'
out of range) with no changes made. void Fl_Tree_Item::select | ( | int | val = 1 |
) | [inline] |
Change the item's selection state to the optionally specified 'val'.
If 'val' is not specified, the item will be selected.
int Fl_Tree_Item::select_all | ( | ) | [inline] |
Select item and all its children.
Returns count of how many items were in the 'deselected' state, ie. how many items were "changed".
void Fl_Tree_Item::show_self | ( | const char * | indent = "" |
) | const |
Print the tree as 'ascii art' to stdout.
Used mainly for debugging.
void Fl_Tree_Item::show_widgets | ( | ) | [protected] |
int Fl_Tree_Item::swap_children | ( | Fl_Tree_Item * | a, | |
Fl_Tree_Item * | b | |||
) |
Swap two of our immediate children, given item pointers.
Use e.g. for sorting.
This method is SLOW because it involves linear lookups.
For speed, use swap_children(int,int) instead.
[in] | a,b | The item ptrs of the two items to swap. Both must be immediate children of the current item. |
'a'
or 'b'
is not our child. void Fl_Tree_Item::swap_children | ( | int | ax, | |
int | bx | |||
) |
Swap two of our children, given two child index values 'ax'
and 'bx'
.
Use e.g. for sorting.
This method is FAST, and does not involve lookups.
No range checking is done on either index value.
[in] | ax,bx | the index of the items to swap |
void Fl_Tree_Item::update_prev_next | ( | int | index | ) |
Update our _prev_sibling and _next_sibling pointers to point to neighbors given index
as being our current position in the parent's item array.
Call this whenever items in the array are added/removed/moved/swapped/etc.
[in] | index | Our index# in the parent. Special case if index=-1: become an orphan; null out all parent/sibling associations. |
void Fl_Tree_Item::usericon | ( | Fl_Image * | val | ) | [inline] |
Set the item's user icon to an Fl_Image.
Use '0' to disable. No internal copy is made, caller must manage icon's memory.
Note, if you expect your items to be deactivated(), use userdeicon(Fl_Image*) to set up a 'grayed out' version of your icon to be used for display.
int Fl_Tree_Item::visible_r | ( | ) | const |
int Fl_Tree_Item::w | ( | ) | const [inline] |
The entire item's width to right edge of Fl_Tree's inner width within scrollbars.