|
Home · All Namespaces · All Classes · Main Classes · Grouped Classes · Modules · Functions |
The Q3ListBox widget provides a list of selectable, read-only items. More...
#include <Q3ListBox>
This class is part of the Qt 3 support library. It is provided to keep old source code working. We strongly advise against using it in new code. See Porting to Qt 4 for more information.
Inherits Q3ScrollView.
|
|
The Q3ListBox widget provides a list of selectable, read-only items.
This is typically a single-column list in which either no item or one item is selected, but it can also be used in many other ways.
Q3ListBox will add scroll bars as necessary, but it isn't intended for really big lists. If you want more than a few thousand items, it's probably better to use a different widget mainly because the scroll bars won't provide very good navigation, but also because Q3ListBox may become slow with huge lists. (See Q3ListView and Q3Table for possible alternatives.)
There are a variety of selection modes described in the Q3ListBox::SelectionMode documentation. The default is Single selection mode, but you can change it using setSelectionMode(). (setMultiSelection() is still provided for compatibility with Qt 1.x. We recommend using setSelectionMode() in all code.)
Because Q3ListBox offers multiple selection it must display keyboard focus and selection state separately. Therefore there are functions both to set the selection state of an item, i.e. setSelected(), and to set which item displays keyboard focus, i.e. setCurrentItem().
The list box normally arranges its items in a single column and adds a vertical scroll bar if required. It is possible to have a different fixed number of columns (setColumnMode()), or as many columns as will fit in the list box's assigned screen space (setColumnMode(FitToWidth)), or to have a fixed number of rows (setRowMode()) or as many rows as will fit in the list box's assigned screen space (setRowMode(FitToHeight)). In all these cases Q3ListBox will add scroll bars, as appropriate, in at least one direction.
If multiple rows are used, each row can be as high as necessary (the normal setting), or you can request that all items will have the same height by calling setVariableHeight(false). The same applies to a column's width, see setVariableWidth().
The Q3ListBox's items are Q3ListBoxItem objects. Q3ListBox provides methods to insert new items as strings, as pixmaps, and as Q3ListBoxItem * (insertItem() with various arguments), and to replace an existing item with a new string, pixmap or Q3ListBoxItem (changeItem() with various arguments). You can also remove items singly with removeItem() or clear() the entire list box. Note that if you create a Q3ListBoxItem yourself and insert it, Q3ListBox takes ownership of the item.
You can also create a Q3ListBoxItem, such as Q3ListBoxText or Q3ListBoxPixmap, with the list box as first parameter. The item will then append itself. When you delete an item it is automatically removed from the list box.
The list of items can be arbitrarily large; Q3ListBox will add scroll bars if necessary. Q3ListBox can display a single-column (the common case) or multiple-columns, and offers both single and multiple selection. Q3ListBox does not support multiple-column items (but Q3ListView and Q3Table do), or tree hierarchies (but Q3ListView does).
The list box items can be accessed both as Q3ListBoxItem objects (recommended) and using integer indexes (the original Q3ListBox implementation used an array of strings internally, and the API still supports this mode of operation). Everything can be done using the new objects, and most things can be done using indexes.
Each item in a Q3ListBox contains a Q3ListBoxItem. One of the items can be the current item. The currentChanged() signal and the highlighted() signal are emitted when a new item becomes current, e.g. because the user clicks on it or Q3ListBox::setCurrentItem() is called. The selected() signal is emitted when the user double-clicks on an item or presses Enter on the current item.
If the user does not select anything, no signals are emitted and currentItem() returns -1.
A list box has Qt::WheelFocus as a default focusPolicy(), i.e. it can get keyboard focus by tabbing, clicking and through the use of the mouse wheel.
New items can be inserted using insertItem(), insertStrList() or insertStringList().
By default, vertical and horizontal scroll bars are added and removed as necessary. setHScrollBarMode() and setVScrollBarMode() can be used to change this policy.
If you need to insert types other than strings and pixmaps, you must define new classes which inherit Q3ListBoxItem.
Warning: The list box assumes ownership of all list box items and will delete them when it does not need them any more.
See also Q3ListView, QComboBox, and QButtonGroup.
This typedef is used in Q3IconView's API for values that are OR'd combinations of StringComparisonMode values.
See also StringComparisonMode.
This enum type is used to specify how Q3ListBox lays out its rows and columns.
| Constant | Value | Description |
|---|---|---|
| Q3ListBox::FixedNumber | 0 | There is a fixed number of rows (or columns). |
| Q3ListBox::FitToWidth | 1 | There are as many columns as will fit on-screen. |
| Q3ListBox::FitToHeight | FitToWidth | There are as many rows as will fit on-screen. |
| Q3ListBox::Variable | ? | There are as many rows as are required by the column mode. (Or as many columns as required by the row mode.) |
Example: When you call setRowMode(FitToHeight), columnMode() automatically becomes Variable to accommodate the row mode you've set.
This enumerated type is used by Q3ListBox to indicate how it reacts to selection by the user.
| Constant | Value | Description |
|---|---|---|
| Q3ListBox::Single | 0 | When the user selects an item, any already-selected item becomes unselected and the user cannot unselect the selected item. This means that the user can never clear the selection, even though the selection may be cleared by the application programmer using Q3ListBox::clearSelection(). |
| Q3ListBox::Multi | 1 | When the user selects an item the selection status of that item is toggled and the other items are left alone. |
| Q3ListBox::Extended | 2 | When the user selects an item the selection is cleared and the new item selected. However, if the user presses the Ctrl key when clicking on an item, the clicked item gets toggled and all other items are left untouched. And if the user presses the Shift key while clicking on an item, all items between the current item and the clicked item get selected or unselected, depending on the state of the clicked item. Also, multiple items can be selected by dragging the mouse while the left mouse button is kept pressed. |
| Q3ListBox::NoSelection | 3 | Items cannot be selected. |
In other words, Single is a real single-selection list box, Multi is a real multi-selection list box, Extended is a list box in which users can select multiple items but usually want to select either just one or a range of contiguous items, and NoSelection is for a list box where the user can look but not touch.
This enum type is used to set the string comparison mode when searching for an item. We'll refer to the string being searched as the 'target' string.
| Constant | Value | Description |
|---|---|---|
| Q3ListBox::CaseSensitive | 0x00001 | The strings must match case sensitively. |
| Q3ListBox::ExactMatch | 0x00010 | The target and search strings must match exactly. |
| Q3ListBox::BeginsWith | 0x00002 | The target string begins with the search string. |
| Q3ListBox::EndsWith | 0x00004 | The target string ends with the search string. |
| Q3ListBox::Contains | 0x00008 | The target string contains the search string. |
If you OR these flags together (excluding CaseSensitive), the search criteria be applied in the following order: ExactMatch, BeginsWith, EndsWith, Contains.
Matching is case-insensitive unless CaseSensitive is set. CaseSensitive can be OR-ed with any combination of the other flags.
See also ComparisonFlags.
This property holds the column layout mode for this list box.
setColumnMode() sets the layout mode and adjusts the number of displayed columns. The row layout mode automatically becomes Variable, unless the column mode is Variable.
Access functions:
See also setRowMode(), rowMode, and numColumns.
This property holds the number of items in the list box.
Access functions:
This property holds the current highlighted item.
When setting this property, the highlighting is moved to the item and the list box scrolled as necessary.
If no item is current, currentItem() returns -1.
Access functions:
This property holds the text of the current item.
This is equivalent to text(currentItem()).
Access functions:
This property holds whether or not the list box is in Multi selection mode.
Consider using the Q3ListBox::selectionMode property instead of this property.
When setting this property, Multi selection mode is used if set to true and to Single selection mode if set to false.
When getting this property, true is returned if the list box is in Multi selection mode or Extended selection mode, and false if it is in Single selection mode or NoSelection mode.
Access functions:
See also selectionMode.
This property holds the number of columns in the list box.
This is normally 1, but can be different if Q3ListBox::columnMode or Q3ListBox::rowMode has been set.
Access functions:
See also columnMode, rowMode, and numRows.
This property holds the number of visible items.
Both partially and entirely visible items are counted.
Access functions:
This property holds the number of rows in the list box.
This is equal to the number of items in the default single-column layout, but can be different.
Access functions:
See also columnMode, rowMode, and numColumns.
This property holds the row layout mode for this list box.
This property is normally Variable.
setRowMode() sets the layout mode and adjusts the number of displayed rows. The column layout mode automatically becomes Variable, unless the row mode is Variable.
Access functions:
See also columnMode.
This property holds the selection mode of the list box.
Sets the list box's selection mode, which may be one of Single (the default), Extended, Multi or NoSelection.
Access functions:
See also SelectionMode.
This property holds the index of an item at the top of the screen.
When getting this property and the listbox has multiple columns, an arbitrary item is selected and returned.
When setting this property, the list box is scrolled so the item at position index in the list is displayed in the top row of the list box.
Access functions:
This property holds whether this list box has variable-height rows.
When the list box has variable-height rows (the default), each row is as high as the highest item in that row. When it has same-sized rows, all rows are as high as the highest item in the list box.
Access functions:
See also variableWidth.
This property holds whether this list box has variable-width columns.
When the list box has variable-width columns, each column is as wide as the widest item in that column. When it has same-sized columns (the default), all columns are as wide as the widest item in the list box.
Access functions:
See also variableHeight.
Constructs a new empty list box called name and with parent parent and widget attributes f.
This constructor sets the Qt::WA_StaticContent and the Qt::WA_NoBackground attributes to boost performance when drawing Q3ListBoxItems. This may be unsuitable for custom Q3ListBoxItem classes, in which case Qt::WA_StaticContents and Qt::WA_NoBackground should be cleared on the viewport() after construction.
Destroys the list box. Deletes all list box items.
Use hScrollBarMode() instead. Returns true if the horizontal scrollbar mode is set to Auto.
See also setAutoBottomScrollBar().
Use dragAutoScroll() instead. This function always returns true.
See also setAutoScroll().
Use vScrollBarMode() instead. Returns true if the vertical scrollbar mode is Auto.
See also setAutoScrollBar().
Returns true. Qt always updates automatically.
See also setAutoUpdate().
Use hScrollBarMode() instead. Returns true if the horizontal scrollbar mode is not AlwaysOff.
See also setBottomScrollBar().
Use itemHeight(i) instead.
This is an overloaded member function, provided for convenience.
Use itemHeight() instead.
Use maxItemWidth() instead.
This is an overloaded member function, provided for convenience.
Use maxItemWidth(i) instead.
If there is a current item, the list box is scrolled so that this item is displayed centered.
See also Q3ListBox::ensureCurrentVisible().
Replaces the item at position index with lbi. If index is negative or too large, changeItem() does nothing.
The item that has been changed will become selected.
See also insertItem() and removeItem().
This is an overloaded member function, provided for convenience.
Replaces the item at position index with a new list box text item with text text.
The operation is ignored if index is out of range.
See also insertItem() and removeItem().
This is an overloaded member function, provided for convenience.
Replaces the item at position index with a new list box pixmap item with pixmap pixmap.
The operation is ignored if index is out of range.
See also insertItem() and removeItem().
This is an overloaded member function, provided for convenience.
Replaces the item at position index with a new list box pixmap item with pixmap pixmap and text text.
The operation is ignored if index is out of range.
See also insertItem() and removeItem().
Deletes all the items in the list.
See also removeItem().
Deselects all items, if possible.
Note that a Single selection list box will automatically select an item if it has keyboard focus.
This signal is emitted when the user clicks any mouse button. If item is not 0, the cursor is on item. If item is 0, the mouse cursor isn't on any item.
Note that you must not delete any Q3ListBoxItem objects in slots connected to this signal.
This is an overloaded member function, provided for convenience.
This signal is emitted when the user clicks any mouse button. If item is not 0, the cursor is on item. If item is 0, the mouse cursor isn't on any item.
pnt is the position of the mouse cursor in the global coordinate system (QMouseEvent::globalPos()). (If the click's press and release differs by a pixel or two, pnt is the position at release time.)
Note that you must not delete any Q3ListBoxItem objects in slots connected to this signal.
This signal is emitted when the user invokes a context menu with the right mouse button or with special system keys, with item being the item under the mouse cursor or the current item, respectively.
pos is the position for the context menu in the global coordinate system.
This signal is emitted when the user makes a new item the current item. item is the new current list box item.
See also setCurrentItem() and currentItem().
This function does the hard layout work. You should never need to call it.
This signal is emitted whenever an item is double-clicked. It's emitted on the second button press, not the second button release. If item is not 0, the cursor is on item. If item is 0, the mouse cursor isn't on any item.
Returns true. Dragging always selects.
See also setDragSelect().
Ensures that the current item is visible.
Finds the first list box item that has the text text and returns it, or returns 0 of no such item could be found. If ComparisonFlags are specified in compare then these flags are used, otherwise the default is a case-insensitive, "begins with" search.
This is an overloaded member function, provided for convenience.
Use index(itemAt(yPos)) instead.
Returns the first item in this list box. If the list box is empty, returns 0.
This signal is emitted when the user makes a new item the current item. index is the index of the new current item.
See also currentChanged(), selected(), currentItem(), and selectionChanged().
This is an overloaded member function, provided for convenience.
This signal is emitted when the user makes a new item the current item.
See also currentChanged(), selected(), currentItem(), and selectionChanged().
This is an overloaded member function, provided for convenience.
This signal is emitted when the user makes a new item the current item and the item is (or has) as string. The argument is the new current item's text.
See also currentChanged(), selected(), currentItem(), and selectionChanged().
Using this method is quite inefficient. We suggest to use insertItem() for inserting and sort() afterwards.
Inserts lbi at its sorted position in the list box and returns the position.
All items must be inserted with inSort() to maintain the sorting order. inSort() treats any pixmap (or user-defined type) as lexicographically less than any string.
See also insertItem() and sort().
This is an overloaded member function, provided for convenience.
Using this method is quite inefficient. We suggest to use insertItem() for inserting and sort() afterwards.
Inserts a new item of text at its sorted position in the list box and returns the position.
All items must be inserted with inSort() to maintain the sorting order. inSort() treats any pixmap (or user-defined type) as lexicographically less than any string.
See also insertItem() and sort().
Returns the index of lbi, or -1 if the item is not in this list box or lbi is 0.
See also item().
Inserts the item lbi into the list at position index.
If index is negative or larger than the number of items in the list box, lbi is inserted at the end of the list.
See also insertStrList().
This is an overloaded member function, provided for convenience.
Inserts the item lbi into the list after the item after, or at the beginning if after is 0.
See also insertStrList().
This is an overloaded member function, provided for convenience.
Inserts a new list box text item with the text text into the list at position index.
If index is negative, text is inserted at the end of the list.
See also insertStrList().
This is an overloaded member function, provided for convenience.
Inserts a new list box pixmap item with the pixmap pixmap into the list at position index.
If index is negative, pixmap is inserted at the end of the list.
See also insertStrList().
This is an overloaded member function, provided for convenience.
Inserts a new list box pixmap item with the pixmap pixmap and the text text into the list at position index.
If index is negative, pixmap is inserted at the end of the list.
See also insertStrList().
Inserts the numStrings strings of the array strings into the list at position index.
If index is negative, insertStrList() inserts strings at the end of the list. If index is too large, the operation is ignored.
Warning: This function uses const char * rather than QString, so we recommend against using it. It is provided so that legacy code will continue to work, and so that programs that certainly will not need to handle code outside a single 8-bit locale can use it. See insertStringList() which uses real QStrings.
Warning: This function is never significantly faster than a loop around insertItem().
See also insertItem() and insertStringList().
Inserts the string list list into the list at position index.
If index is negative, list is inserted at the end of the list. If index is too large, the operation is ignored.
Warning: This function is never significantly faster than a loop around insertItem().
See also insertItem() and insertStrList().
Inverts the selection. Only works in Multi and Extended selection mode.
Returns true if the user is selecting items using a rubber band rectangle; otherwise returns false.
Returns true if item i is selected; otherwise returns false.
This is an overloaded member function, provided for convenience.
Returns true if item i is selected; otherwise returns false.
Returns a pointer to the item at position index, or 0 if index is out of bounds.
See also index().
Returns the item at point p, specified in viewport coordinates, or a 0 if there is no item at p.
Use contentsToViewport() to convert between widget coordinates and viewport coordinates.
Returns the height in pixels of the item with index index. index defaults to 0.
If index is too large, this function returns 0.
Returns the rectangle on the screen that item occupies in viewport()'s coordinates, or an invalid rectangle if item is 0 or is not currently visible.
Returns true if the item at position index is at least partly visible; otherwise returns false.
This is an overloaded member function, provided for convenience.
Returns true if item is at least partly visible; otherwise returns false.
Returns the width of the widest item in the list box.
This signal is emitted when the user clicks mouse button button. If item is not 0, the cursor is on item. If item is 0, the mouse cursor isn't on any item.
pos is the position of the mouse cursor in the global coordinate system (QMouseEvent::globalPos()). (If the click's press and release differs by a pixel or two, pos is the position at release time.)
Note that you must not delete any Q3ListBoxItem objects in slots connected to this signal.
This signal is emitted when the user presses mouse button button. If item is not 0, the cursor is on item. If item is 0, the mouse cursor isn't on any item.
pos is the position of the mouse cursor in the global coordinate system (QMouseEvent::globalPos()).
Note that you must not delete any Q3ListBoxItem objects in slots connected to this signal.
Use numColumns() instead.
This signal is emitted when the user moves the mouse cursor onto an item, similar to the QWidget::enterEvent() function. i is the Q3ListBoxItem that the mouse has moved on.
This signal is emitted when the user moves the mouse cursor from an item to an empty part of the list box.
Provided for compatibility with the old Q3ListBox. We recommend using Q3ListBoxItem::paint() instead.
Repaints the cell at row, col using painter p.
Returns a pointer to the pixmap at position index, or 0 if there is no pixmap there.
See also text().
This signal is emitted when the user presses any mouse button. If item is not 0, the cursor is on item. If item is 0, the mouse cursor isn't on any item.
Note that you must not delete any Q3ListBoxItem objects in slots connected to this signal.
This is an overloaded member function, provided for convenience.
This signal is emitted when the user presses any mouse button. If item is not 0, the cursor is on item. If item is 0, the mouse cursor isn't on any item.
pnt is the position of the mouse cursor in the global coordinate system (QMouseEvent::globalPos()).
Note that you must not delete any Q3ListBoxItem objects in slots connected to this signal.
See also mouseButtonPressed(), rightButtonPressed(), and clicked().
Removes and deletes the item at position index. If index is equal to currentItem(), a new item becomes current and the currentChanged() and highlighted() signals are emitted.
See also insertItem() and clear().
This signal is emitted when Enter or Return is pressed. The item passed in the argument is currentItem().
This signal is emitted when the right button is clicked. The item is the item that the button was clicked on (which could be 0 if no item was clicked on), and the point is where the click took place in global coordinates.
This signal is emitted when the right button is pressed. The item is the item that the button was pressed over (which could be 0 if no item was pressed over), and the point is where the press took place in global coordinates.
Use vScrollBarMode() instead. Returns true if the vertical scrollbar mode is not AlwaysOff.
See also setScrollBar().
In Multi and Extended modes, this function sets all items to be selected if select is true, and to be unselected if select is false.
In Single and NoSelection modes, this function only changes the selection status of currentItem().
This signal is emitted when the user double-clicks on an item or presses Enter on the current item. index is the index of the selected item.
See also setSelected(), currentChanged(), highlighted(), and selectionChanged().
This is an overloaded member function, provided for convenience.
This signal is emitted when the user double-clicks on an item or presses Enter on the current item.
See also currentChanged(), highlighted(), and selectionChanged().
This is an overloaded member function, provided for convenience.
This signal is emitted when the user double-clicks on an item or presses Enter on the current item, and the item is (or has) a string. The argument is the text of the selected item.
See also currentChanged(), highlighted(), and selectionChanged().
Returns the selected item if the list box is in single-selection mode and an item is selected.
If no items are selected or the list box is in another selection mode this function returns 0.
See also setSelected() and setMultiSelection().
This signal is emitted when the selection set of a list box changes. This signal is emitted in each selection mode. If the user selects five items by drag-selecting, Q3ListBox tries to emit just one selectionChanged() signal so the signal can be connected to computationally expensive slots.
See also selected() and currentItem().
This is an overloaded member function, provided for convenience.
This signal is emitted when the selection in a Single selection list box changes. item is the newly selected list box item.
See also selected() and currentItem().
Use setHScrollBarMode() instead.
If enable is true, pass Auto as the argument to setHScrollBarMode(); otherwise, pass AlwaysOff.
See also autoBottomScrollBar().
Use setDragAutoScroll(b) instead.
See also autoScroll().
Use setVScrollBarMode() instead.
If enable is true, pass Auto as the argument to setVScrollBarMode(); otherwise, pass AlwaysOff.
See also autoScrollBar().
Does nothing. Qt always updates automatically. The b parameter is ignored.
See also autoUpdate().
Scrolls the list box so the item at position index in the list is displayed in the bottom row of the list box.
See also setTopItem().
Use setHScrollBarMode() instead.
If enable is true, pass AlwaysOn as the argument to setHScrollBarMode(); otherwise, pass AlwaysOff.
See also bottomScrollBar().
Does nothing. Dragging always selects. The b parameter is ignored.
See also dragSelect().
Use setRowMode(lines) instead.
Use setVScrollBarMode() instead.
If enable is true, pass AlwaysOn as the argument to setVScrollBarMode(); otherwise, pass AlwaysOff.
See also scrollBar().
Selects item if select is true or unselects it if select is false, and repaints the item appropriately.
If the list box is a Single selection list box and select is true, setSelected() calls setCurrentItem().
If the list box is a Single selection list box, select is false, setSelected() calls clearSelection().
See also selected(), setMultiSelection(), setCurrentItem(), clearSelection(), and currentItem().
This is an overloaded member function, provided for convenience.
If select is true the item at position index is selected; otherwise the item is deselected.
Does nothing. Qt always scrolls smoothly. The b parameter is ignored.
See also smoothScrolling().
Returns false. Qt always scrolls smoothly.
See also setSmoothScrolling().
If ascending is true sorts the items in ascending order; otherwise sorts in descending order.
To compare the items, the text (Q3ListBoxItem::text()) of the items is used.
Removes item from the list box and causes an update of the screen display. The item is not deleted. You should normally not need to call this function because Q3ListBoxItem::~Q3ListBoxItem() calls it. The normal way to delete an item is with delete.
See also Q3ListBox::insertItem().
Returns the text at position index, or an empty string if there is no text at that position.
See also pixmap().
Toggles the selection status of currentItem() and repaints if the list box is a Multi selection list box.
See also setMultiSelection().
Use contentsHeight() instead.
Use contentsWidth() instead.
Ensures that a single paint event will occur at the end of the current event loop iteration. If doLayout is true, the layout is also redone.
Does nothing. Qt automatically updates.
Repaints the item at position index in the list.
This is an overloaded member function, provided for convenience.
Repaints the Q3ListBoxItem i.
| Copyright © 2008 Nokia | Trademarks | Qt 4.4.3 |