Combo

Instances of this class are controls that allow the user to choose an item from a list of items, or optionally enter a new value by typing it into an editable text field. Often, <code>Combo</code>s are used in the same place where a single selection <code>List</code> widget could be used but space is limited. A <code>Combo</code> takes less space than a <code>List</code> widget and shows similar information. <p> Note: Since <code>Combo</code>s can contain both a list and an editable text field, it is possible to confuse methods which access one versus the other (compare for example, <code>clearSelection()</code> and <code>deselectAll()</code>). The API documentation is careful to indicate either "the receiver's list" or the "the receiver's text field" to distinguish between the two cases. </p><p> Note that although this class is a subclass of <code>Composite</code>, it does not make sense to add children to it, or set a layout on it. </p> <dl> <dt><b>Styles:</b></dt> <dd>DROP_DOWN, READ_ONLY, SIMPLE</dd> <dt><b>Events:</b></dt> <dd>DefaultSelection, Modify, Selection, Verify</dd> </dl> <p> Note: Only one of the styles DROP_DOWN and SIMPLE may be specified. </p><p> IMPORTANT: This class is <em>not</em> intended to be subclassed. </p>

@see List @see <a href="http://www.eclipse.org/swt/snippets/#combo">Combo snippets</a> @see <a href="http://www.eclipse.org/swt/examples.php">SWT Example: ControlExample</a> @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>

class Combo : Composite {
GtkWidget* buttonHandle;
GtkWidget* entryHandle;
GtkWidget* listHandle;
GtkWidget* textRenderer;
GtkWidget* cellHandle;
GtkWidget* popupHandle;
int lastEventTime;
int visibleCount;
GdkEventKey* gdkEventKey;
int fixStart;
int fixEnd;
String[] items;
bool ignoreSelect;
bool lockText;
int INNER_BORDER;
}

Constructors

this
this(Composite parent, int style)

Constructs a new instance of this class given its parent and a style value describing its behavior and appearance. <p> The style value is either one of the style constants defined in class <code>SWT</code> which is applicable to instances of this class, or must be built by <em>bitwise OR</em>'ing together (that is, using the <code>int</code> "|" operator) two or more of those <code>SWT</code> style constants. The class description lists the style constants that are applicable to the class. Style bits are also inherited from superclasses. </p>

Members

Functions

add
void add(String string)

Adds the argument to the end of the receiver's list.

add
void add(String string, int index)

Adds the argument to the receiver's list at the given zero-relative index. <p> Note: To add an item at the end of the list, use the result of calling <code>getItemCount()</code> as the index or use <code>add(String)</code>. </p>

addModifyListener
void addModifyListener(ModifyListener listener)

Adds the listener to the collection of listeners who will be notified when the receiver's text is modified, by sending it one of the messages defined in the <code>ModifyListener</code> interface.

addSelectionListener
void addSelectionListener(SelectionListener listener)

Adds the listener to the collection of listeners who will be notified when the user changes the receiver's selection, by sending it one of the messages defined in the <code>SelectionListener</code> interface. <p> <code>widgetSelected</code> is called when the user changes the combo's list selection. <code>widgetDefaultSelected</code> is typically called when ENTER is pressed the combo's text area. </p>

addVerifyListener
void addVerifyListener(VerifyListener listener)

Adds the listener to the collection of listeners who will be notified when the receiver's text is verified, by sending it one of the messages defined in the <code>VerifyListener</code> interface.

clearSelection
void clearSelection()

Sets the selection in the receiver's text field to an empty selection starting just before the first character. If the text field is editable, this has the effect of placing the i-beam at the start of the text. <p> Note: To clear the selected items in the receiver's list, use <code>deselectAll()</code>. </p>

copy
void copy()

Copies the selected text. <p> The current selection is copied to the clipboard. </p>

cut
void cut()

Cuts the selected text. <p> The current selection is first copied to the clipboard and then deleted from the widget. </p>

deselect
void deselect(int index)

Deselects the item at the given zero-relative index in the receiver's list. If the item at the index was already deselected, it remains deselected. Indices that are out of range are ignored.

deselectAll
void deselectAll()

Deselects all selected items in the receiver's list. <p> Note: To clear the selection in the receiver's text field, use <code>clearSelection()</code>. </p>

getItem
String getItem(int index)

Returns the item at the given, zero-relative index in the receiver's list. Throws an exception if the index is out of range.

getItemCount
int getItemCount()

Returns the number of items contained in the receiver's list.

getItemHeight
int getItemHeight()

Returns the height of the area which would be used to display <em>one</em> of the items in the receiver's list.

getItems
String[] getItems()

Returns a (possibly empty) array of <code>String</code>s which are the items in the receiver's list. <p> Note: This is not the actual structure used by the receiver to maintain its list of items, so modifying the array will not affect the receiver. </p>

getListVisible
bool getListVisible()

Returns <code>true</code> if the receiver's list is visible, and <code>false</code> otherwise. <p> If one of the receiver's ancestors is not visible or some other condition makes the receiver not visible, this method may still indicate that it is considered visible even though it may not actually be showing. </p>

getOrientation
int getOrientation()

Returns the orientation of the receiver.

getSelection
Point getSelection()

Returns a <code>Point</code> whose x coordinate is the character position representing the start of the selection in the receiver's text field, and whose y coordinate is the character position representing the end of the selection. An "empty" selection is indicated by the x and y coordinates having the same value. <p> Indexing is zero based. The range of a selection is from 0..N where N is the number of characters in the widget. </p>

getSelectionIndex
int getSelectionIndex()

Returns the zero-relative index of the item which is currently selected in the receiver's list, or -1 if no item is selected.

getText
String getText()

Returns a string containing a copy of the contents of the receiver's text field, or an empty string if there are no contents.

getTextHeight
int getTextHeight()

Returns the height of the receivers's text field.

getTextLimit
int getTextLimit()

Returns the maximum number of characters that the receiver's text field is capable of holding. If this has not been changed by <code>setTextLimit()</code>, it will be the constant <code>Combo.LIMIT</code>.

getVisibleItemCount
int getVisibleItemCount()

Gets the number of items that are visible in the drop down portion of the receiver's list. <p> Note: This operation is a hint and is not supported on platforms that do not have this concept. </p>

indexOf
int indexOf(String string)

Searches the receiver's list starting at the first item (index 0) until an item is found that is equal to the argument, and returns the index of that item. If no item is found, returns -1.

indexOf
int indexOf(String string, int start)

Searches the receiver's list starting at the given, zero-relative index until an item is found that is equal to the argument, and returns the index of that item. If no item is found or the starting index is out of range, returns -1.

paste
void paste()

Pastes text from clipboard. <p> The selected text is deleted from the widget and new text inserted from the clipboard. </p>

remove
void remove(int index)

Removes the item from the receiver's list at the given zero-relative index.

remove
void remove(int start, int end)

Removes the items from the receiver's list which are between the given zero-relative start and end indices (inclusive).

remove
void remove(String string)

Searches the receiver's list starting at the first item until an item is found that is equal to the argument, and removes that item from the list.

removeAll
void removeAll()

Removes all of the items from the receiver's list and clear the contents of receiver's text field. <p> @exception SWTException <ul> <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> </ul>

removeModifyListener
void removeModifyListener(ModifyListener listener)

Removes the listener from the collection of listeners who will be notified when the receiver's text is modified.

removeSelectionListener
void removeSelectionListener(SelectionListener listener)

Removes the listener from the collection of listeners who will be notified when the user changes the receiver's selection.

removeVerifyListener
void removeVerifyListener(VerifyListener listener)

Removes the listener from the collection of listeners who will be notified when the control is verified.

select
void select(int index)

Selects the item at the given zero-relative index in the receiver's list. If the item at the index was already selected, it remains selected. Indices that are out of range are ignored.

setItem
void setItem(int index, String string)

Sets the text of the item in the receiver's list at the given zero-relative index to the string argument.

setItems
void setItems(String[] items)

Sets the receiver's list to be the given array of items.

setListVisible
void setListVisible(bool visible)

Marks the receiver's list as visible if the argument is <code>true</code>, and marks it invisible otherwise. <p> If one of the receiver's ancestors is not visible or some other condition makes the receiver not visible, marking it visible may not actually cause it to be displayed. </p>

setOrientation
void setOrientation(int orientation)

Sets the orientation of the receiver, which must be one of the constants <code>SWT.LEFT_TO_RIGHT</code> or <code>SWT.RIGHT_TO_LEFT</code>. <p>

setSelection
void setSelection(Point selection)

Sets the selection in the receiver's text field to the range specified by the argument whose x coordinate is the start of the selection and whose y coordinate is the end of the selection.

setText
void setText(String string)

Sets the contents of the receiver's text field to the given string. <p> Note: The text field in a <code>Combo</code> is typically only capable of displaying a single line of text. Thus, setting the text to a string containing line breaks or other special characters will probably cause it to display incorrectly. </p>

setTextLimit
void setTextLimit(int limit)

Sets the maximum number of characters that the receiver's text field is capable of holding to be the argument. <p> To reset this value to the default, use <code>setTextLimit(Combo.LIMIT)</code>. Specifying a limit value larger than <code>Combo.LIMIT</code> sets the receiver's limit to <code>Combo.LIMIT</code>. </p> @param limit new text limit

setVisibleItemCount
void setVisibleItemCount(int count)

Sets the number of items that are visible in the drop down portion of the receiver's list. <p> Note: This operation is a hint and is not supported on platforms that do not have this concept. </p>

Static variables

LIMIT
int LIMIT;

the operating system limit for the number of characters that the text field in an instance of this class can hold

Inherited Members

From Composite

changed
void changed(Control[] changed)

Clears any data that has been cached by a Layout for all widgets that are in the parent hierarchy of the changed control up to and including the receiver. If an ancestor does not have a layout, it is skipped.

getBackgroundMode
int getBackgroundMode()

Returns the receiver's background drawing mode. This will be one of the following constants defined in class <code>SWT</code>: <code>INHERIT_NONE</code>, <code>INHERIT_DEFAULT</code>, <code>INHERTIT_FORCE</code>.

getChildren
Control[] getChildren()

Returns a (possibly empty) array containing the receiver's children. Children are returned in the order that they are drawn. The topmost control appears at the beginning of the array. Subsequent controls draw beneath this control and appear later in the array. <p> Note: This is not the actual structure used by the receiver to maintain its list of children, so modifying the array will not affect the receiver. </p>

getLayout
Layout getLayout()

Returns layout which is associated with the receiver, or null if one has not been set.

getLayoutDeferred
bool getLayoutDeferred()

Returns <code>true</code> if the receiver has deferred the performing of layout, and <code>false</code> otherwise.

getTabList
Control[] getTabList()

Gets the (possibly empty) tabbing order for the control.

isLayoutDeferred
bool isLayoutDeferred()

Returns <code>true</code> if the receiver or any ancestor up to and including the receiver's nearest ancestor shell has deferred the performing of layouts. Otherwise, <code>false</code> is returned.

layout
void layout()

If the receiver has a layout, asks the layout to <em>lay out</em> (that is, set the size and location of) the receiver's children. If the receiver does not have a layout, do nothing. <p> This is equivalent to calling <code>layout(true)</code>. </p> <p> Note: Layout is different from painting. If a child is moved or resized such that an area in the parent is exposed, then the parent will paint. If no child is affected, the parent will not paint. </p>

layout
void layout(bool changed)

If the receiver has a layout, asks the layout to <em>lay out</em> (that is, set the size and location of) the receiver's children. If the argument is <code>true</code> the layout must not rely on any information it has cached about the immediate children. If it is <code>false</code> the layout may (potentially) optimize the work it is doing by assuming that none of the receiver's children has changed state since the last layout. If the receiver does not have a layout, do nothing. <p> If a child is resized as a result of a call to layout, the resize event will invoke the layout of the child. The layout will cascade down through all child widgets in the receiver's widget tree until a child is encountered that does not resize. Note that a layout due to a resize will not flush any cached information (same as <code>layout(false)</code>). </p> <p> Note: Layout is different from painting. If a child is moved or resized such that an area in the parent is exposed, then the parent will paint. If no child is affected, the parent will not paint. </p>

layout
void layout(bool changed, bool all)

If the receiver has a layout, asks the layout to <em>lay out</em> (that is, set the size and location of) the receiver's children. If the changed argument is <code>true</code> the layout must not rely on any information it has cached about its children. If it is <code>false</code> the layout may (potentially) optimize the work it is doing by assuming that none of the receiver's children has changed state since the last layout. If the all argument is <code>true</code> the layout will cascade down through all child widgets in the receiver's widget tree, regardless of whether the child has changed size. The changed argument is applied to all layouts. If the all argument is <code>false</code>, the layout will <em>not</em> cascade down through all child widgets in the receiver's widget tree. However, if a child is resized as a result of a call to layout, the resize event will invoke the layout of the child. Note that a layout due to a resize will not flush any cached information (same as <code>layout(false)</code>). </p> <p> Note: Layout is different from painting. If a child is moved or resized such that an area in the parent is exposed, then the parent will paint. If no child is affected, the parent will not paint. </p>

layout
void layout(Control[] changed)

Forces a lay out (that is, sets the size and location) of all widgets that are in the parent hierarchy of the changed control up to and including the receiver. The layouts in the hierarchy must not rely on any information cached about the changed control or any of its ancestors. The layout may (potentially) optimize the work it is doing by assuming that none of the peers of the changed control have changed state since the last layout. If an ancestor does not have a layout, skip it. <p> Note: Layout is different from painting. If a child is moved or resized such that an area in the parent is exposed, then the parent will paint. If no child is affected, the parent will not paint. </p>

setBackgroundMode
void setBackgroundMode(int mode)

Sets the background drawing mode to the argument which should be one of the following constants defined in class <code>SWT</code>: <code>INHERIT_NONE</code>, <code>INHERIT_DEFAULT</code>, <code>INHERIT_FORCE</code>.

setLayout
void setLayout(Layout layout)

Sets the layout which is associated with the receiver to be the argument which may be null.

setLayoutDeferred
void setLayoutDeferred(bool defer)

If the argument is <code>true</code>, causes subsequent layout operations in the receiver or any of its children to be ignored. No layout of any kind can occur in the receiver or any of its children until the flag is set to false. Layout operations that occurred while the flag was <code>true</code> are remembered and when the flag is set to <code>false</code>, the layout operations are performed in an optimized manner. Nested calls to this method are stacked.

setTabList
void setTabList(Control[] tabList)

Sets the tabbing order for the specified controls to match the order that they occur in the argument list.

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