basiccomboboxui.java

JAVA 所有包

    /**
     * Gets the insets from the JComboBox.
     */
    protected Insets getInsets() {
        return comboBox.getInsets();
    }

    //
    // end Utility Methods
    //====================


    //===============================
    // begin Painting Utility Methods
    //

    /**
     * Paints the currently selected item.
     */
    public void paintCurrentValue(Graphics g,Rectangle bounds,boolean hasFocus) {
        ListCellRenderer renderer = comboBox.getRenderer();
        Component c;

        if ( hasFocus && !isPopupVisible(comboBox) ) {
            c = renderer.getListCellRendererComponent( listBox,
                                                       comboBox.getSelectedItem(),
                                                       -1,
                                                       true,
                                                       false );
        }
        else {
            c = renderer.getListCellRendererComponent( listBox,
                                                       comboBox.getSelectedItem(),
                                                       -1,
                                                       false,
                                                       false );
            c.setBackground(UIManager.getColor("ComboBox.background"));
        }
        c.setFont(comboBox.getFont());
        if ( hasFocus && !isPopupVisible(comboBox) ) {
            c.setForeground(listBox.getSelectionForeground());
            c.setBackground(listBox.getSelectionBackground());
        }
        else {
            if ( comboBox.isEnabled() ) {
                c.setForeground(comboBox.getForeground());
                c.setBackground(comboBox.getBackground());
            }
            else {
                c.setForeground(DefaultLookup.getColor(
                         comboBox, this, "ComboBox.disabledForeground", null));
                c.setBackground(DefaultLookup.getColor(
                         comboBox, this, "ComboBox.disabledBackground", null));
            }
        }

        // Fix for 4238829: should lay out the JPanel.
        boolean shouldValidate = false;
        if (c instanceof JPanel)  {
            shouldValidate = true;
        }

        currentValuePane.paintComponent(g,c,comboBox,bounds.x,bounds.y,
                                        bounds.width,bounds.height, shouldValidate);
    }

    /**
     * Paints the background of the currently selected item.
     */
    public void paintCurrentValueBackground(Graphics g,Rectangle bounds,boolean hasFocus) {
        Color t = g.getColor();
        if ( comboBox.isEnabled() )
            g.setColor(DefaultLookup.getColor(comboBox, this,
                                              "ComboBox.background", null));
        else
            g.setColor(DefaultLookup.getColor(comboBox, this,
                                     "ComboBox.disabledBackground", null));
        g.fillRect(bounds.x,bounds.y,bounds.width,bounds.height);
        g.setColor(t);
    }

    /**
     * Repaint the currently selected item.
     */
    void repaintCurrentValue() {
        Rectangle r = rectangleForCurrentValue();
        comboBox.repaint(r.x,r.y,r.width,r.height);
    }

    //
    // end Painting Utility Methods
    //=============================


    //===============================
    // begin Size Utility Methods
    //

    /** 
     * Return the default size of an empty display area of the combo box using
     * the current renderer and font.
     *
     * @return the size of an empty display area
     * @see #getDisplaySize
     */
    protected Dimension getDefaultSize() {
	// Calculates the height and width using the default text renderer
	Dimension d = getSizeForComponent(getDefaultListCellRenderer().getListCellRendererComponent(listBox, " ", -1, false, false));

        return new Dimension(d.width, d.height);
    }

    /** 
     * Returns the calculated size of the display area. The display area is the
     * portion of the combo box in which the selected item is displayed. This 
     * method will use the prototype display value if it has been set. 
     * <p>
     * For combo boxes with a non trivial number of items, it is recommended to
     * use a prototype display value to significantly speed up the display 
     * size calculation.
     * 
     * @return the size of the display area calculated from the combo box items
     * @see javax.swing.JComboBox#setPrototypeDisplayValue
     */
    protected Dimension getDisplaySize() {
        if (!isDisplaySizeDirty)  {
            return new Dimension(cachedDisplaySize);
        }
	Dimension result = new Dimension();
        
        ListCellRenderer renderer = comboBox.getRenderer();
        if (renderer == null)  {
            renderer = new DefaultListCellRenderer();
        }

        sameBaseline = true;

        Object prototypeValue = comboBox.getPrototypeDisplayValue();
        if (prototypeValue != null)  {
            // Calculates the dimension based on the prototype value
            result = getSizeForComponent(renderer.getListCellRendererComponent(listBox, 
									       prototypeValue,
									       -1, false, false));
        } else {
            // Calculate the dimension by iterating over all the elements in the combo
            // box list.
            ComboBoxModel model = comboBox.getModel();
            int modelSize = model.getSize();
            int baseline = -1;
	    Dimension d;

            Component cpn;
            
            if (modelSize > 0 ) {
                for (int i = 0; i < modelSize ; i++ ) {
                    // Calculates the maximum height and width based on the largest
                    // element
                    Object value = model.getElementAt(i);
                    Component c = renderer.getListCellRendererComponent(
                            listBox, value, -1, false, false);
                    d = getSizeForComponent(c);
                    if (sameBaseline && value != null &&
                            (!(value instanceof String) || !"".equals(value))) {
                        int newBaseline = c.getBaseline(d.width, d.height);
                        if (newBaseline == -1) {
                            sameBaseline = false;
                        }
                        else if (baseline == -1) {
                            baseline = newBaseline;
                        }
                        else if (baseline != newBaseline) {
                            sameBaseline = false;
                        }
                    }
                    result.width = Math.max(result.width,d.width);
                    result.height = Math.max(result.height,d.height);
                }
            } else {
		result = getDefaultSize();
		if (comboBox.isEditable()) {
		    result.width = 100;
		}
            }
        }

	if ( comboBox.isEditable() ) {
	    Dimension d = editor.getPreferredSize();
	    result.width = Math.max(result.width,d.width);
	    result.height = Math.max(result.height,d.height);
	}
        
        // Set the cached value
        cachedDisplaySize.setSize(result.width, result.height);
        isDisplaySizeDirty = false;

        return result;
    }

    /**
     * This has been refactored out in hopes that it may be investigated and
     * simplified for the next major release. adding/removing
     * the component to the currentValuePane and changing the font may be 
     * redundant operations.
     */
    private Dimension getSizeForComponent(Component comp) {
	currentValuePane.add(comp);
	comp.setFont(comboBox.getFont());
	Dimension d = comp.getPreferredSize();
	currentValuePane.remove(comp);
	return d;
    }
	

    //
    // end Size Utility Methods
    //=============================


    //=================================
    // begin Keyboard Action Management
    //

    /**
     * Adds keyboard actions to the JComboBox.  Actions on enter and esc are already
     * supplied.  Add more actions as you need them.
     */
    protected void installKeyboardActions() {
	InputMap km = getInputMap(JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);
	SwingUtilities.replaceUIInputMap(comboBox, JComponent.
			     WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, km);


        LazyActionMap.installLazyActionMap(comboBox, BasicComboBoxUI.class,
                                           "ComboBox.actionMap");
    }

    InputMap getInputMap(int condition) {
	if (condition == JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT) {
	    return (InputMap)DefaultLookup.get(comboBox, this,
                                               "ComboBox.ancestorInputMap");
	}
	return null;
    }

    boolean isTableCellEditor() {
	return isTableCellEditor;
    }

    /**
     * Removes the focus InputMap and ActionMap.
     */
    protected void uninstallKeyboardActions() {
	SwingUtilities.replaceUIInputMap(comboBox, JComponent.
				 WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, null);
	SwingUtilities.replaceUIActionMap(comboBox, null);
    }


    //
    // Actions
    // 
    private static class Actions extends UIAction {
        private static final String HIDE = "hidePopup";
        private static final String DOWN = "selectNext";
        private static final String DOWN_2 = "selectNext2";
        private static final String TOGGLE = "togglePopup";
        private static final String TOGGLE_2 = "spacePopup";
        private static final String UP = "selectPrevious";
        private static final String UP_2 = "selectPrevious2";
        private static final String ENTER = "enterPressed";
        private static final String PAGE_DOWN = "pageDownPassThrough";
        private static final String PAGE_UP = "pageUpPassThrough";
        private static final String HOME = "homePassThrough";
        private static final String END = "endPassThrough";

        Actions(String name) {
            super(name);
        }

	public void actionPerformed( ActionEvent e ) {
            String key = getName();
            JComboBox comboBox = (JComboBox)e.getSource();
            BasicComboBoxUI ui = (BasicComboBoxUI)BasicLookAndFeel.getUIOfType(
                                  comboBox.getUI(), BasicComboBoxUI.class);
            if (key == HIDE) {
                comboBox.firePopupMenuCanceled();
                comboBox.setPopupVisible(false);
            }
            else if (key == PAGE_DOWN || key == PAGE_UP ||
                     key == HOME || key == END) {
                int index = getNextIndex(comboBox, key);
                if (index >= 0 && index < comboBox.getItemCount()) {
                    comboBox.setSelectedIndex(index);
                }
            }
            else if (key == DOWN) {
                if (comboBox.isShowing() ) {
                    if ( comboBox.isPopupVisible() ) {
                        if (ui != null) {
                            ui.selectNextPossibleValue();
                        }
                    } else {
                        comboBox.setPopupVisible(true);
                    }
                }
            }
            else if (key == DOWN_2) {
		// Special case in which pressing the arrow keys will not 
		// make the popup appear - except for editable combo boxes
                // and combo boxes inside a table.
                if (comboBox.isShowing() ) {
                    if ( (comboBox.isEditable() ||
                            (ui != null && ui.isTableCellEditor()))
                         && !comboBox.isPopupVisible() ) {
                        comboBox.setPopupVisible(true);
                    } else {
                        if (ui != null) {
                            ui.selectNextPossibleValue();
                        }
                    }
                }
            }
            else if (key == TOGGLE || key == TOGGLE_2) {
                if (ui != null && (key == TOGGLE || !comboBox.isEditable())) {
                    if ( ui.isTableCellEditor() ) {
                        // Forces the selection of the list item if the
                        // combo box is in a JTable.
                        comboBox.setSelectedIndex(ui.popup.getList().
                                                  getSelectedIndex());
                    } 
                    else {
                        comboBox.setPopupVisible(!comboBox.isPopupVisible());
                    }
                }
            }
            else if (key == UP) {
		if (ui != null) {
                    if (ui.isPopupVisible(comboBox)) {
                        ui.selectPreviousPossibleValue();
                    }
                    else if (DefaultLookup.getBoolean(comboBox, ui,
                                    "ComboBox.showPopupOnNavigation", false)) {
                        ui.setPopupVisible(comboBox, true);
                    }
                }
            }
	    else if (key == UP_2) {
                 // Special case in which pressing the arrow keys will not 
                 // make the popup appear - except for editable combo boxes.
                 if (comboBox.isShowing() && ui != null) {
                     if ( comboBox.isEditable() && !comboBox.isPopupVisible()) {
			 comboBox.setPopupVisible(true);
                     } else {
			 ui.selectPreviousPossibleValue();
                     }
                 }
             }

            else if (key == ENTER) {
                if (comboBox.isPopupVisible()) {
                    // Forces the selection of the list item
                    boolean isEnterSelectablePopup = 
                            UIManager.getBoolean("ComboBox.isEnterSelectablePopup");  
                    if (!comboBox.isEditable() || isEnterSelectablePopup) {
                        Object listItem = ui.popup.getList().getSelectedValue();
                        if (listItem != null) {
                            comboBox.getModel().setSelectedItem(listItem);
                            // Ensure that JComboBox.actionPerformed()
                            // doesn't set editor value as selected item
                            comboBox.getEditor().setItem(listItem);
                        }
                    }
                    comboBox.setPopupVisible(false);
                } 
                else {
                    // Call the default button binding.