diff options
Diffstat (limited to 'libjava/javax/swing/JComboBox.java')
| -rw-r--r-- | libjava/javax/swing/JComboBox.java | 247 |
1 files changed, 145 insertions, 102 deletions
diff --git a/libjava/javax/swing/JComboBox.java b/libjava/javax/swing/JComboBox.java index 86f20b099eb..4e2a88110fc 100644 --- a/libjava/javax/swing/JComboBox.java +++ b/libjava/javax/swing/JComboBox.java @@ -1,5 +1,5 @@ /* JComboBox.java -- - Copyright (C) 2002, 2004 Free Software Foundation, Inc. + Copyright (C) 2002, 2004, 2005 Free Software Foundation, Inc. This file is part of GNU Classpath. @@ -60,7 +60,6 @@ import javax.swing.event.ListDataListener; import javax.swing.event.PopupMenuListener; import javax.swing.plaf.ComboBoxUI; - /** * JComboBox. JComboBox is a container, that keeps track of elements added to * it by the user. JComboBox allows user to select any item in its list and @@ -69,12 +68,14 @@ import javax.swing.plaf.ComboBoxUI; * * @author Andrew Selkirk * @author Olga Rodimina + * @author Robert Schuster */ public class JComboBox extends JComponent implements ItemSelectable, ListDataListener, ActionListener, Accessible { + private static final long serialVersionUID = 5654585963292734470L; /** @@ -91,43 +92,7 @@ public class JComboBox extends JComponent implements ItemSelectable, * Maximum number of rows that should be visible by default in the * JComboBox's popup */ - public static final int DEFAULT_MAXIMUM_ROW_COUNT = 8; - - /** - * Fired in a PropertyChangeEvent when the 'editable' property changes. - */ - public static final String EDITABLE_CHANGED_PROPERTY = "editable"; - - /** - * Fired in a PropertyChangeEvent when the 'maximumRowCount' property - * changes. - */ - public static final String MAXIMUM_ROW_COUNT_CHANGED_PROPERTY = "maximumRowCount"; - - /** - * Fired in a PropertyChangeEvent when the 'enabled' property changes. - */ - public static final String ENABLED_CHANGED_PROPERTY = "enabled"; - - /** - * Fired in a PropertyChangeEvent when the 'renderer' property changes. - */ - public static final String RENDERER_CHANGED_PROPERTY = "renderer"; - - /** - * Fired in a PropertyChangeEvent when the 'editor' property changes. - */ - public static final String EDITOR_CHANGED_PROPERTY = "editor"; - - /** - * Fired in a PropertyChangeEvent when the 'dataModel' property changes. - */ - public static final String MODEL_CHANGED_PROPERTY = "dataModel"; - - /** - * name for the UI delegate for this combo box. - */ - private static final String uiClassID = "ComboBoxUI"; + private static final int DEFAULT_MAXIMUM_ROW_COUNT = 8; /** * dataModel used by JComboBox to keep track of its list data and currently @@ -143,7 +108,7 @@ public class JComboBox extends JComponent implements ItemSelectable, protected ListCellRenderer renderer; /** - * editor that is responsible for editting an object in a combo box list + * Editor that is responsible for editing an object in a combo box list. */ protected ComboBoxEditor editor; @@ -191,8 +156,9 @@ public class JComboBox extends JComponent implements ItemSelectable, private Object prototypeDisplayValue; /** - * Constructs JComboBox object with specified data model for it. The first - * item in the specified data model is selected by default. + * Constructs JComboBox object with specified data model for it. + * <p>Note that the JComboBox will not change the value that + * is preselected by your ComboBoxModel implementation.</p> * * @param model Data model that will be used by this JComboBox to keep track * of its list of items. @@ -205,10 +171,6 @@ public class JComboBox extends JComponent implements ItemSelectable, setModel(model); setActionCommand("comboBoxChanged"); - // by default set selected item to the first element in the combo box - if (getItemCount() != 0) - setSelectedItem(getItemAt(0)); - lightWeightPopupEnabled = true; isEditable = false; @@ -300,7 +262,7 @@ public class JComboBox extends JComponent implements ItemSelectable, */ public String getUIClassID() { - return uiClassID; + return "ComboBoxUI"; } /** @@ -322,21 +284,29 @@ public class JComboBox extends JComponent implements ItemSelectable, */ public void setModel(ComboBoxModel newDataModel) { - if (this.dataModel == newDataModel) - return; - if (this.dataModel != null) - // remove all listeners currently registered with the model. - dataModel.removeListDataListener(this); + // dataModel is null if it this method is called from inside the constructors. + if(dataModel != null) { + // Prevents unneccessary updates. + if (dataModel == newDataModel) + return; - ComboBoxModel oldDataModel = this.dataModel; - this.dataModel = newDataModel; + // Removes itself (as DataListener) from the to-be-replaced model. + dataModel.removeListDataListener(this); + } + + /* Adds itself as a DataListener to the new model. + * It is intentioned that this operation will fail with a NullPointerException if the + * caller delivered a null argument. + */ + newDataModel.addListDataListener(this); - if (this.dataModel != null) - // register all listeners with the new data model - dataModel.addListDataListener(this); + // Stores old data model for event notification. + ComboBoxModel oldDataModel = dataModel; + dataModel = newDataModel; - firePropertyChange(MODEL_CHANGED_PROPERTY, oldDataModel, this.dataModel); + // Notifies the listeners of the model change. + firePropertyChange("model", oldDataModel, dataModel); } /** @@ -351,8 +321,8 @@ public class JComboBox extends JComponent implements ItemSelectable, /** * This method sets JComboBox's popup to be either lightweight or - * heavyweight. If 'enabled' is true then lightweight popup is used and - * heavyweight otherwise. By default lightweight popup is used to display + * heavyweight. If 'enabled' is true then lightweight popup is used and + * heavyweight otherwise. By default lightweight popup is used to display * this JComboBox's elements. * * @param enabled indicates if lightweight popup or heavyweight popup should @@ -360,7 +330,7 @@ public class JComboBox extends JComponent implements ItemSelectable, */ public void setLightWeightPopupEnabled(boolean enabled) { - this.lightWeightPopupEnabled = enabled; + lightWeightPopupEnabled = enabled; } /** @@ -388,10 +358,10 @@ public class JComboBox extends JComponent implements ItemSelectable, */ public void setEditable(boolean editable) { - if (this.isEditable != editable) + if (isEditable != editable) { - this.isEditable = editable; - firePropertyChange(EDITABLE_CHANGED_PROPERTY, ! isEditable, isEditable); + isEditable = editable; + firePropertyChange("editable", ! isEditable, isEditable); } } @@ -407,10 +377,10 @@ public class JComboBox extends JComponent implements ItemSelectable, { if (maximumRowCount != rowCount) { - int oldMaximumRowCount = this.maximumRowCount; - this.maximumRowCount = rowCount; - firePropertyChange(MAXIMUM_ROW_COUNT_CHANGED_PROPERTY, - oldMaximumRowCount, this.maximumRowCount); + int oldMaximumRowCount = maximumRowCount; + maximumRowCount = rowCount; + firePropertyChange("maximumRowCount", + oldMaximumRowCount, maximumRowCount); } } @@ -437,12 +407,12 @@ public class JComboBox extends JComponent implements ItemSelectable, */ public void setRenderer(ListCellRenderer aRenderer) { - if (this.renderer != aRenderer) + if (renderer != aRenderer) { - ListCellRenderer oldRenderer = this.renderer; - this.renderer = aRenderer; - firePropertyChange(RENDERER_CHANGED_PROPERTY, oldRenderer, - this.renderer); + ListCellRenderer oldRenderer = renderer; + renderer = aRenderer; + firePropertyChange("renderer", oldRenderer, + renderer); } } @@ -477,11 +447,11 @@ public class JComboBox extends JComponent implements ItemSelectable, if (editor != null) editor.addActionListener(this); - firePropertyChange(EDITOR_CHANGED_PROPERTY, oldEditor, editor); + firePropertyChange("editor", oldEditor, editor); } /** - * Returns editor component that is responsible for displaying/editting + * Returns editor component that is responsible for displaying/editing * selected item in the combo box. * * @return ComboBoxEditor @@ -503,45 +473,76 @@ public class JComboBox extends JComponent implements ItemSelectable, /** * Returns currently selected item in the combo box. + * The result may be <code>null</code> to indicate that nothing is + * currently selected. * * @return element that is currently selected in this combo box. */ public Object getSelectedItem() { - Object item = dataModel.getSelectedItem(); - - if (item == null && getItemCount() != 0) - item = getItemAt(0); - - return item; + return dataModel.getSelectedItem(); } /** - * Forces JComboBox to select component located in the given index in the + * Forces JComboBox to select component located in the given index in the * combo box. + * <p>If the index is below -1 or exceeds the upper bound an + * <code>IllegalArgumentException</code> is thrown.<p/> + * <p>If the index is -1 then no item gets selected.</p> * * @param index index specifying location of the component that should be * selected. */ public void setSelectedIndex(int index) { - // FIXME: if index == -1 then nothing should be selected - setSelectedItem(dataModel.getElementAt(index)); + if(index < -1 || index >= dataModel.getSize()) { + // Fails because index is out of bounds. + throw new IllegalArgumentException("illegal index: " + index); + } else { + /* Selects the item at the given index or clears the selection if the + * index value is -1. + */ + setSelectedItem((index == -1) ? null : dataModel.getElementAt(index)); + } } /** * Returns index of the item that is currently selected in the combo box. * If no item is currently selected, then -1 is returned. + * + * <p>Note: For performance reasons you should minimize invocation of this + * method. If the data model is not an instance of + * <code>DefaultComboBoxModel</code> the complexity is O(n) where + * n is the number of elements in the combo box.</p> * - * @return int index specifying location of the currently selected item in + * @return int Index specifying location of the currently selected item in * the combo box or -1 if nothing is selected in the combo box. */ public int getSelectedIndex() { Object selectedItem = getSelectedItem(); - if (selectedItem != null && (dataModel instanceof DefaultComboBoxModel)) - return ((DefaultComboBoxModel) dataModel).getIndexOf(selectedItem); + + if (selectedItem != null) { + + if(dataModel instanceof DefaultComboBoxModel) { + // Uses special method of DefaultComboBoxModel to retrieve the index. + return ((DefaultComboBoxModel) dataModel).getIndexOf(selectedItem); + } else { + // Iterates over all items to retrieve the index. + int size = dataModel.getSize(); + + for(int i=0; i < size; i++) { + Object o = dataModel.getElementAt(i); + + // XXX: Is special handling of ComparableS neccessary? + if((selectedItem != null) ? selectedItem.equals(o) : o == null) { + return i; + } + } + } + } + // returns that no item is currently selected return -1; } @@ -550,60 +551,104 @@ public class JComboBox extends JComponent implements ItemSelectable, return prototypeDisplayValue; } - public void setPrototypeDisplayValue(Object prototypeDisplayValue) + public void setPrototypeDisplayValue(Object newPrototypeDisplayValue) { - this.prototypeDisplayValue = prototypeDisplayValue; + prototypeDisplayValue = newPrototypeDisplayValue; } /** * This method adds given element to this JComboBox. + * <p>A <code>RuntimeException</code> is thrown if the data model is not + * an instance of {@link MutableComboBoxModel}.</p> * * @param element element to add */ public void addItem(Object element) { - ((MutableComboBoxModel) dataModel).addElement(element); + if(dataModel instanceof MutableComboBoxModel) { + ((MutableComboBoxModel) dataModel).addElement(element); + } else { + throw new RuntimeException("Unable to add the item because the data model it is not an instance of MutableComboBoxModel."); + } } /** - * Inserts given element at the specified index to this JComboBox + * Inserts given element at the specified index to this JComboBox. + * <p>A <code>RuntimeException</code> is thrown if the data model is not + * an instance of {@link MutableComboBoxModel}.</p> * * @param element element to insert * @param index position where to insert the element */ public void insertItemAt(Object element, int index) { - ((MutableComboBoxModel) dataModel).insertElementAt(element, index); + if(dataModel instanceof MutableComboBoxModel) { + ((MutableComboBoxModel) dataModel).insertElementAt(element, index); + } else { + throw new RuntimeException("Unable to insert the item because the data model it is not an instance of MutableComboBoxModel."); + } } /** * This method removes given element from this JComboBox. + * <p>A <code>RuntimeException</code> is thrown if the data model is not + * an instance of {@link MutableComboBoxModel}.</p> * * @param element element to remove */ public void removeItem(Object element) { - ((MutableComboBoxModel) dataModel).removeElement(element); + if(dataModel instanceof MutableComboBoxModel) { + ((MutableComboBoxModel) dataModel).removeElement(element); + } else { + throw new RuntimeException("Unable to remove the item because the data model it is not an instance of MutableComboBoxModel."); + } } /** * This method remove element location in the specified index in the * JComboBox. + * <p>A <code>RuntimeException</code> is thrown if the data model is not + * an instance of {@link MutableComboBoxModel}.</p> * * @param index index specifying position of the element to remove */ public void removeItemAt(int index) { - ((MutableComboBoxModel) dataModel).removeElementAt(index); + if(dataModel instanceof MutableComboBoxModel) { + ((MutableComboBoxModel) dataModel).removeElementAt(index); + } else { + throw new RuntimeException("Unable to remove the item because the data model it is not an instance of MutableComboBoxModel."); + } } /** * This method removes all elements from this JComboBox. + * <p>A <code>RuntimeException</code> is thrown if the data model is not + * an instance of {@link MutableComboBoxModel}.</p> + * */ public void removeAllItems() { - if (dataModel instanceof DefaultComboBoxModel) - ((DefaultComboBoxModel) dataModel).removeAllElements(); + if (dataModel instanceof DefaultComboBoxModel) { + // Uses special method if we have a DefaultComboBoxModel. + ((DefaultComboBoxModel) dataModel).removeAllElements(); + } else if(dataModel instanceof MutableComboBoxModel){ + // Iterates over all items and removes each. + MutableComboBoxModel mcbm = (MutableComboBoxModel) dataModel; + + /* We intentionally remove the items backwards to support + * models which shift their content to the beginning (e.g. + * linked lists) + */ + for(int i=mcbm.getSize()-1; i >= 0; i--) { + mcbm.removeElementAt(i); + } + + } else { + throw new RuntimeException("Unable to remove the items because the data model it is not an instance of MutableComboBoxModel."); + } + } /** @@ -801,8 +846,7 @@ public class JComboBox extends JComponent implements ItemSelectable, */ public Object[] getSelectedObjects() { - Object selectedObject = getSelectedItem(); - return new Object[] { selectedObject }; + return new Object[] { getSelectedItem() }; } /** @@ -887,8 +931,7 @@ public class JComboBox extends JComponent implements ItemSelectable, if (enabled != oldEnabled) { super.setEnabled(enabled); - firePropertyChange(ENABLED_CHANGED_PROPERTY, oldEnabled, - (boolean) enabled); + firePropertyChange("enabled", oldEnabled, enabled); } } @@ -951,7 +994,7 @@ public class JComboBox extends JComponent implements ItemSelectable, */ public int getItemCount() { - return ((DefaultComboBoxModel) dataModel).getSize(); + return dataModel.getSize(); } /** @@ -963,7 +1006,7 @@ public class JComboBox extends JComponent implements ItemSelectable, */ public Object getItemAt(int index) { - return ((MutableComboBoxModel) dataModel).getElementAt(index); + return dataModel.getElementAt(index); } /** |