datechooserpanel.java

该源代码为一些通用的程序

        }

        this.buttons = new JButton[42];
        for (int i = 0; i < 42; i++) {
            final JButton b = new JButton("");
            b.setMargin(new Insets(1, 1, 1, 1));
            b.setName(Integer.toString(i));
            b.setFont(this.dateFont);
            b.setFocusPainted(false);
            b.setActionCommand("dateButtonClicked");
            b.addActionListener(this);
            this.buttons[i] = b;
            p.add(b);
        }
        return p;

    }

    /**
     * Returns the button color according to the specified date.
     *
     * @param theDate the date.
     * @return the color.
     */
    private Color getButtonColor(final Calendar theDate) {
        if (equalDates(theDate, this.chosenDate)) {
            return this.chosenDateButtonColor;
        }
        else if (theDate.get(Calendar.MONTH) == this.chosenDate.get(
                Calendar.MONTH)) {
            return this.chosenMonthButtonColor;
        }
        else {
            return this.chosenOtherButtonColor;
        }
    }

    /**
     * Returns true if the two dates are equal (time of day is ignored).
     *
     * @param c1 the first date.
     * @param c2 the second date.
     * @return boolean.
     */
    private boolean equalDates(final Calendar c1, final Calendar c2) {
        if ((c1.get(Calendar.DATE) == c2.get(Calendar.DATE))
            && (c1.get(Calendar.MONTH) == c2.get(Calendar.MONTH))
            && (c1.get(Calendar.YEAR) == c2.get(Calendar.YEAR))) {
            return true;
        }
        else {
            return false;
        }
    }

    /**
     * Returns the first date that is visible in the grid.  This should always 
     * be in the month preceding the month of the selected date.
     *
     * @return the date.
     */
    private Calendar getFirstVisibleDate() {
        final Calendar c = Calendar.getInstance();
        c.set(this.chosenDate.get(Calendar.YEAR), this.chosenDate.get(
                Calendar.MONTH), 1);
        c.add(Calendar.DATE, -1);
        while (c.get(Calendar.DAY_OF_WEEK) != getFirstDayOfWeek()) {
            c.add(Calendar.DATE, -1);
        }
        return c;
    }

    /**
     * Returns the first day of the week (controls the labels in the date 
     * panel).
     *
     * @return the first day of the week.
     */
    private int getFirstDayOfWeek() {
        return this.firstDayOfWeek;
    }

    /**
     * Update the button labels and colors to reflect date selection.
     */
    private void refreshButtons() {
        final Calendar c = getFirstVisibleDate();
        for (int i = 0; i < 42; i++) {
            final JButton b = this.buttons[i];
            b.setText(Integer.toString(c.get(Calendar.DATE)));
            b.setBackground(getButtonColor(c));
            c.add(Calendar.DATE, 1);
        }
    }

    /**
     * Changes the contents of the year selection JComboBox to reflect the 
     * chosen date and the year range.
     */
    private void refreshYearSelector() {
        if (!this.refreshing) {
            this.refreshing = true;
            this.yearSelector.removeAllItems();
            final Integer[] years = getYears(this.chosenDate.get(
                    Calendar.YEAR));
            for (int i = 0; i < years.length; i++) {
                this.yearSelector.addItem(years[i]);
            }
            this.yearSelector.setSelectedItem(new Integer(this.chosenDate.get(
                    Calendar.YEAR)));
            this.refreshing = false;
        }
    }

    /**
     * Returns a vector of years preceding and following the specified year.  
     * The number of years preceding and following is determined by the 
     * yearSelectionRange attribute.
     *
     * @param chosenYear the selected year.
     * @return a vector of years.
     */
    private Integer[] getYears(final int chosenYear) {
        final int size = this.yearSelectionRange * 2 + 1;
        final int start = chosenYear - this.yearSelectionRange;

        final Integer[] years = new Integer[size];
        for (int i = 0; i < size; i++) {
            years[i] = new Integer(i + start);
        }
        return years;
    }

    /**
     * Constructs a panel containing two JComboBoxes (for the month and year) 
     * and a button (to reset the date to TODAY).
     *
     * @return the panel.
     */
    private JPanel constructSelectionPanel() {
        final JPanel p = new JPanel();

        final int minMonth = this.chosenDate.getMinimum(Calendar.MONTH);
        final int maxMonth = this.chosenDate.getMaximum(Calendar.MONTH);
        final String[] months = new String[maxMonth - minMonth + 1];
        System.arraycopy(SerialDate.getMonths(), minMonth, months, 0, 
                months.length);

        this.monthSelector = new JComboBox(months);
        this.monthSelector.addActionListener(this);
        this.monthSelector.setActionCommand("monthSelectionChanged");
        p.add(this.monthSelector);

        this.yearSelector = new JComboBox(getYears(0));
        this.yearSelector.addActionListener(this);
        this.yearSelector.setActionCommand("yearSelectionChanged");
        p.add(this.yearSelector);

        return p;
    }

    /**
     * Returns a panel that appears at the bottom of the calendar panel - 
     * contains a button for selecting today's date.
     *
     * @return the panel.
     */
    private JPanel constructControlPanel() {

        final JPanel p = new JPanel();
        p.setBorder(BorderFactory.createEmptyBorder(2, 5, 2, 5));
        this.todayButton = new JButton("Today");
        this.todayButton.addActionListener(this);
        this.todayButton.setActionCommand("todayButtonClicked");
        p.add(this.todayButton);
        return p;

    }

    /**
     * Returns the color for the currently selected date.
     *
     * @return a color.
     */
    public Color getChosenDateButtonColor() {
        return this.chosenDateButtonColor;
    }

    /**
     * Redefines the color for the currently selected date.
     *
     * @param chosenDateButtonColor the new color
     */
    public void setChosenDateButtonColor(final Color chosenDateButtonColor) {
        if (chosenDateButtonColor == null) {
            throw new NullPointerException("UIColor must not be null.");
        }
        final Color oldValue = this.chosenDateButtonColor;
        this.chosenDateButtonColor = chosenDateButtonColor;
        refreshButtons();
        firePropertyChange("chosenDateButtonColor", oldValue, 
                chosenDateButtonColor);
    }

    /**
     * Returns the color for the buttons representing the current month.
     *
     * @return the color for the current month.
     */
    public Color getChosenMonthButtonColor() {
        return this.chosenMonthButtonColor;
    }

    /**
     * Defines the color for the buttons representing the current month.
     *
     * @param chosenMonthButtonColor the color for the current month.
     */
    public void setChosenMonthButtonColor(final Color chosenMonthButtonColor) {
        if (chosenMonthButtonColor == null) {
            throw new NullPointerException("UIColor must not be null.");
        }
        final Color oldValue = this.chosenMonthButtonColor;
        this.chosenMonthButtonColor = chosenMonthButtonColor;
        refreshButtons();
        firePropertyChange("chosenMonthButtonColor", oldValue, 
                chosenMonthButtonColor);
    }

    /**
     * Returns the color for the buttons representing the other months.
     *
     * @return a color.
     */
    public Color getChosenOtherButtonColor() {
        return this.chosenOtherButtonColor;
    }

    /**
     * Redefines the color for the buttons representing the other months.
     *
     * @param chosenOtherButtonColor a color.
     */
    public void setChosenOtherButtonColor(final Color chosenOtherButtonColor) {
        if (chosenOtherButtonColor == null) {
            throw new NullPointerException("UIColor must not be null.");
        }
        final Color oldValue = this.chosenOtherButtonColor;
        this.chosenOtherButtonColor = chosenOtherButtonColor;
        refreshButtons();
        firePropertyChange("chosenOtherButtonColor", oldValue, 
                chosenOtherButtonColor);
    }

    /**
     * Returns the range of years available for selection (defaults to 20).
     * 
     * @return The range.
     */
    public int getYearSelectionRange() {
        return this.yearSelectionRange;
    }

    /**
     * Sets the range of years available for selection.
     * 
     * @param yearSelectionRange  the range.
     */
    public void setYearSelectionRange(final int yearSelectionRange) {
        final int oldYearSelectionRange = this.yearSelectionRange;
        this.yearSelectionRange = yearSelectionRange;
        refreshYearSelector();
        firePropertyChange("yearSelectionRange", oldYearSelectionRange, 
                yearSelectionRange);
    }
}