SimpleScrollPaneLayout.
*/
class SimpleScrollPaneLayout extends ScrollPaneLayout {
protected AbstractButton _scrollUp;
protected AbstractButton _scrollDown;
protected AbstractButton _scrollLeft;
protected AbstractButton _scrollRight;
@Override
public void syncWithScrollPane(JScrollPane sp) {
super.syncWithScrollPane(sp);
if (sp instanceof SimpleScrollPane) {
_scrollUp = ((SimpleScrollPane) sp).getScrollUpButton();
_scrollDown = ((SimpleScrollPane) sp).getScrollDownButton();
_scrollLeft = ((SimpleScrollPane) sp).getScrollLeftButton();
_scrollRight = ((SimpleScrollPane) sp).getScrollRightButton();
}
}
@Override
public void addLayoutComponent(String s, Component c) {
if (SimpleScrollPane.SCROLL_UP_BUTTON.equals(s)) {
_scrollUp = (AbstractButton) addSingletonComponent(_scrollUp, c);
}
else if (SimpleScrollPane.SCROLL_DOWN_BUTTON.equals(s)) {
_scrollDown = (AbstractButton) addSingletonComponent(_scrollDown, c);
}
else if (SimpleScrollPane.SCROLL_LEFT_BUTTON.equals(s)) {
_scrollLeft = (AbstractButton) addSingletonComponent(_scrollLeft, c);
}
else if (SimpleScrollPane.SCROLL_RIGHT_BUTTON.equals(s)) {
_scrollRight = (AbstractButton) addSingletonComponent(_scrollRight, c);
}
else {
super.addLayoutComponent(s, c);
}
}
@Override
public void removeLayoutComponent(Component c) {
if (c == _scrollUp) {
_scrollUp = null;
}
else if (c == _scrollDown) {
_scrollDown = null;
}
else if (c == _scrollLeft) {
_scrollLeft = null;
}
else if (c == _scrollRight) {
_scrollRight = null;
}
else {
super.removeLayoutComponent(c);
}
}
/**
* The preferred size of a ScrollPane is the size of the insets,
* plus the preferred size of the viewport, plus the preferred size of
* the visible headers, plus the preferred size of the scrollbars
* that will appear given the current view and the current
* scrollbar displayPolicies.
* Note that the rowHeader is calculated as part of the preferred width
* and the colHeader is calculated as part of the preferred size.
*
* @param parent the Container that will be laid out
* @return a Dimension object specifying the preferred size of the
* viewport and any scrollbars
* @see javax.swing.ViewportLayout
* @see java.awt.LayoutManager
*/
@Override
public Dimension preferredLayoutSize(Container parent) {
/* Sync the (now obsolete) policy fields with the
* JScrollPane.
*/
JScrollPane scrollPane = (JScrollPane) parent;
vsbPolicy = scrollPane.getVerticalScrollBarPolicy();
hsbPolicy = scrollPane.getHorizontalScrollBarPolicy();
Insets insets = parent.getInsets();
int prefWidth = insets.left + insets.right;
int prefHeight = insets.top + insets.bottom;
/* Note that viewport.getViewSize() is equivalent to
* viewport.getView().getPreferredSize() modulo a null
* view or a view whose size was explicitly set.
*/
Dimension extentSize = null;
Dimension viewSize = null;
Component view = null;
if (viewport != null) {
extentSize = viewport.getPreferredSize();
viewSize = viewport.getViewSize();
view = viewport.getView();
}
/* If there's a viewport add its preferredSize.
*/
if (extentSize != null) {
prefWidth += extentSize.width;
prefHeight += extentSize.height;
}
/* If there's a JScrollPane.viewportBorder, add its insets.
*/
Border viewportBorder = scrollPane.getViewportBorder();
if (viewportBorder != null) {
Insets vpbInsets = viewportBorder.getBorderInsets(parent);
prefWidth += vpbInsets.left + vpbInsets.right;
prefHeight += vpbInsets.top + vpbInsets.bottom;
}
/* If a scrollbar is going to appear, factor its preferred size in.
* If the scrollbars policy is AS_NEEDED, this can be a little
* tricky:
*
* - If the view is a Scrollable then scrollableTracksViewportWidth
* and scrollableTracksViewportHeight can be used to effectively
* disable scrolling (if they're true) in their respective dimensions.
*
* - Assuming that a scrollbar hasn't been disabled by the
* previous constraint, we need to decide if the scrollbar is going
* to appear to correctly compute the JScrollPanes preferred size.
* To do this we compare the preferredSize of the viewport (the
* extentSize) to the preferredSize of the view. Although we're
* not responsible for laying out the view we'll assume that the
* JViewport will always give it its preferredSize.
*/
if (_scrollUp != null && _scrollDown != null && vsbPolicy != VERTICAL_SCROLLBAR_NEVER) {
if (vsbPolicy == VERTICAL_SCROLLBAR_ALWAYS) {
prefHeight += _scrollUp.isVisible() ? _scrollUp.getPreferredSize().height : 0;
prefHeight += _scrollDown.isVisible() ? _scrollDown.getPreferredSize().height : 0;
}
else if ((viewSize != null) && (extentSize != null)) {
boolean canScroll = true;
if (view instanceof Scrollable) {
canScroll = !((Scrollable) view).getScrollableTracksViewportHeight();
}
if (canScroll && (viewSize.height > extentSize.height)) {
prefHeight += _scrollUp.isVisible() ? _scrollUp.getPreferredSize().height : 0;
prefHeight += _scrollDown.isVisible() ? _scrollDown.getPreferredSize().height : 0;
}
}
}
if (_scrollLeft != null && _scrollRight != null && hsbPolicy != HORIZONTAL_SCROLLBAR_NEVER) {
if (hsbPolicy == HORIZONTAL_SCROLLBAR_ALWAYS) {
prefWidth += _scrollLeft.isVisible() ? _scrollLeft.getPreferredSize().width : 0;
prefWidth += _scrollRight.isVisible() ? _scrollRight.getPreferredSize().width : 0;
}
else if ((viewSize != null) && (extentSize != null)) {
boolean canScroll = true;
if (view instanceof Scrollable) {
canScroll = !((Scrollable) view).getScrollableTracksViewportWidth();
}
if (canScroll && (viewSize.width > extentSize.width)) {
prefWidth += _scrollLeft.isVisible() ? _scrollLeft.getPreferredSize().width : 0;
prefWidth += _scrollRight.isVisible() ? _scrollRight.getPreferredSize().width : 0;
}
}
}
return new Dimension(prefWidth, prefHeight);
}
/**
* The minimum size of a ScrollPane is the size of the insets
* plus minimum size of the viewport, plus the scrollpane's
* viewportBorder insets, plus the minimum size
* of the visible headers, plus the minimum size of the
* scrollbars whose displayPolicy isn't NEVER.
*
* @param parent the Container that will be laid out
* @return a Dimension object specifying the minimum size
*/
@Override
public Dimension minimumLayoutSize(Container parent) {
/* Sync the (now obsolete) policy fields with the
* JScrollPane.
*/
JScrollPane scrollPane = (JScrollPane) parent;
vsbPolicy = scrollPane.getVerticalScrollBarPolicy();
hsbPolicy = scrollPane.getHorizontalScrollBarPolicy();
Insets insets = parent.getInsets();
int minWidth = insets.left + insets.right;
int minHeight = insets.top + insets.bottom;
/* If there's a viewport add its minimumSize.
*/
if (viewport != null) {
Dimension size = viewport.getMinimumSize();
minWidth += size.width;
minHeight += size.height;
}
/* If there's a JScrollPane.viewportBorder, add its insets.
*/
Border viewportBorder = scrollPane.getViewportBorder();
if (viewportBorder != null) {
Insets vpbInsets = viewportBorder.getBorderInsets(parent);
minWidth += vpbInsets.left + vpbInsets.right;
minHeight += vpbInsets.top + vpbInsets.bottom;
}
/* If a scrollbar might appear, factor its minimum
* size in.
*/
if (_scrollUp != null && _scrollDown != null && vsbPolicy != VERTICAL_SCROLLBAR_NEVER) {
Dimension size = new Dimension(Math.max(_scrollUp.getMinimumSize().width, _scrollDown.getMinimumSize().width), 0);
size.height += _scrollUp.isVisible() ? _scrollUp.getMinimumSize().height : 0;
size.height += _scrollDown.isVisible() ? _scrollDown.getMinimumSize().height : 0;
minHeight += size.height;
minWidth = Math.max(minWidth, size.width);
}
if (_scrollLeft != null && _scrollLeft != null && hsbPolicy != HORIZONTAL_SCROLLBAR_NEVER) {
Dimension size = new Dimension(0, Math.max(_scrollLeft.getMinimumSize().height, _scrollRight.getMinimumSize().height));
size.width += _scrollLeft.isVisible() ? _scrollLeft.getMinimumSize().width : 0;
size.width += _scrollRight.isVisible() ? _scrollRight.getMinimumSize().width : 0;
minWidth += size.width;
minHeight = Math.max(minHeight, size.height);
}
return new Dimension(minWidth, minHeight);
}
/**
* Lays out the scrollpane. The positioning of components depends on
* the following constraints:
*
displayPolicy
* is ALWAYS, it's treated like the row header with respect to its
* dimensions and is made visible.
*
* null
* viewportBorder, then space is allocated for that.
*
* Container to lay out
*/
@Override
public void layoutContainer(Container parent) {
/* Sync the (now obsolete) policy fields with the
* JScrollPane.
*/
JScrollPane scrollPane = (JScrollPane) parent;
vsbPolicy = scrollPane.getVerticalScrollBarPolicy();
hsbPolicy = scrollPane.getHorizontalScrollBarPolicy();
Rectangle availR = scrollPane.getBounds();
availR.x = availR.y = 0;
Insets insets = parent.getInsets();
availR.x = insets.left;
availR.y = insets.top;
availR.width -= insets.left + insets.right;
availR.height -= insets.top + insets.bottom;
/* If there's a JScrollPane.viewportBorder, remove the
* space it occupies for availR.
*/
Border viewportBorder = scrollPane.getViewportBorder();
Insets vpbInsets;
if (viewportBorder != null) {
vpbInsets = viewportBorder.getBorderInsets(parent);
availR.x += vpbInsets.left;
availR.y += vpbInsets.top;
availR.width -= vpbInsets.left + vpbInsets.right;
availR.height -= vpbInsets.top + vpbInsets.bottom;
}
else {
vpbInsets = new Insets(0, 0, 0, 0);
}
/* At this point availR is the space available for the viewport
* and scrollbars. rowHeadR is correct except for its height and y
* and colHeadR is correct except for its width and x. Once we're
* through computing the dimensions of these three parts we can
* go back and set the dimensions of rowHeadR.height, rowHeadR.y,
* colHeadR.width, colHeadR.x and the bounds for the corners.
*
* We'll decide about putting up scrollbars by comparing the
* viewport views preferred size with the viewports extent
* size (generally just its size). Using the preferredSize is
* reasonable because layout proceeds top down - so we expect
* the viewport to be laid out next. And we assume that the
* viewports layout manager will give the view it's preferred
* size. One exception to this is when the view implements
* Scrollable and Scrollable.getViewTracksViewport{Width,Height}
* methods return true. If the view is tracking the viewports
* width we don't bother with a horizontal scrollbar, similarly
* if view.getViewTracksViewport(Height) is true we don't bother
* with a vertical scrollbar.
*/
Component view = (viewport != null) ? viewport.getView() : null;
Dimension viewPrefSize =
(view != null) ? view.getPreferredSize()
: new Dimension(0, 0);
Dimension extentSize =
(viewport != null) ? viewport.toViewCoordinates(availR.getSize())
: new Dimension(0, 0);
boolean viewTracksViewportWidth = false;
boolean viewTracksViewportHeight = false;
boolean isEmpty = (availR.width < 0 || availR.height < 0);
Scrollable sv;
// Don't bother checking the Scrollable methods if there is no room
// for the viewport, we aren't going to show any scrollbars in this
// case anyway.
if (!isEmpty && view instanceof Scrollable) {
sv = (Scrollable) view;
viewTracksViewportWidth = sv.getScrollableTracksViewportWidth();
viewTracksViewportHeight = sv.getScrollableTracksViewportHeight();
}
else {
sv = null;
}
/* If there's a vertical scrollbar and we need one, allocate
* space for it (we'll make it visible later). A vertical
* scrollbar is considered to be fixed width, arbitrary height.
*/
Rectangle scrollUpR = new Rectangle(0, 0, 0, _scrollUp.getPreferredSize().height);
Rectangle scrollDownR = new Rectangle(0, 0, 0, _scrollDown.getPreferredSize().height);
boolean vsbNeeded;
if (isEmpty) {
vsbNeeded = false;
}
else if (vsbPolicy == VERTICAL_SCROLLBAR_ALWAYS) {
vsbNeeded = true;
}
else if (vsbPolicy == VERTICAL_SCROLLBAR_NEVER) {
vsbNeeded = false;
}
else { // vsbPolicy == VERTICAL_SCROLLBAR_AS_NEEDED
if (!_scrollUp.isEnabled()) {
scrollUpR.height = 0;
}
if (!_scrollDown.isEnabled()) {
scrollDownR.height = 0;
}
vsbNeeded = !viewTracksViewportHeight && (viewPrefSize.height > extentSize.height);
}
if (_scrollUp != null && _scrollDown != null && vsbNeeded) {
adjustForScrollUpAndDown(true, availR, scrollUpR, scrollDownR, vpbInsets);
extentSize = viewport.toViewCoordinates(availR.getSize());
}
/* If there's a horizontal scrollbar and we need one, allocate
* space for it (we'll make it visible later). A horizontal
* scrollbar is considered to be fixed height, arbitrary width.
*/
Rectangle scrollLeftR = new Rectangle(0, 0, _scrollLeft.getPreferredSize().width, 0);
Rectangle scrollRightR = new Rectangle(0, 0, _scrollRight.getPreferredSize().width, 0);
boolean hsbNeeded;
if (isEmpty) {
hsbNeeded = false;
}
else if (hsbPolicy == HORIZONTAL_SCROLLBAR_ALWAYS) {
hsbNeeded = true;
}
else if (hsbPolicy == HORIZONTAL_SCROLLBAR_NEVER) {
hsbNeeded = false;
}
else { // hsbPolicy == HORIZONTAL_SCROLLBAR_AS_NEEDED
if (!_scrollLeft.isEnabled()) {
scrollLeftR.width = 0;
}
if (!_scrollRight.isEnabled()) {
scrollRightR.width = 0;
}
hsbNeeded = !viewTracksViewportWidth && (viewPrefSize.width > extentSize.width);
}
if ((hsb != null) && hsbNeeded) {
adjustForScrollLeftAndRight(true, availR, scrollLeftR, scrollRightR, vpbInsets);
/* If we added the horizontal scrollbar then we've implicitly
* reduced the vertical space available to the viewport.
* As a consequence we may have to add the vertical scrollbar,
* if that hasn't been done so already. Of course we
* don't bother with any of this if the vsbPolicy is NEVER.
*/
if (_scrollUp != null && _scrollDown != null && !vsbNeeded &&
(vsbPolicy != VERTICAL_SCROLLBAR_NEVER)) {
extentSize = viewport.toViewCoordinates(availR.getSize());
vsbNeeded = viewPrefSize.height > extentSize.height;
if (vsbNeeded) {
adjustForScrollUpAndDown(true, availR, scrollUpR, scrollDownR, vpbInsets);
}
}
}
/* Set the size of the viewport first, and then recheck the Scrollable
* methods. Some components base their return values for the Scrollable
* methods on the size of the Viewport, so that if we don't
* ask after resetting the bounds we may have gotten the wrong
* answer.
*/
if (viewport != null) {
viewport.setBounds(availR);
if (sv != null) {
extentSize = viewport.toViewCoordinates(availR.getSize());
boolean oldHSBNeeded = hsbNeeded;
boolean oldVSBNeeded = vsbNeeded;
viewTracksViewportWidth = sv.
getScrollableTracksViewportWidth();
viewTracksViewportHeight = sv.
getScrollableTracksViewportHeight();
if (vsb != null && vsbPolicy == VERTICAL_SCROLLBAR_AS_NEEDED) {
boolean newVSBNeeded = !viewTracksViewportHeight &&
(viewPrefSize.height > extentSize.height);
if (newVSBNeeded != vsbNeeded) {
vsbNeeded = newVSBNeeded;
adjustForScrollUpAndDown(vsbNeeded, availR, scrollUpR, scrollDownR, vpbInsets);
extentSize = viewport.toViewCoordinates(availR.getSize());
}
}
if (hsb != null && hsbPolicy == HORIZONTAL_SCROLLBAR_AS_NEEDED) {
boolean newHSBbNeeded = !viewTracksViewportWidth &&
(viewPrefSize.width > extentSize.width);
if (newHSBbNeeded != hsbNeeded) {
hsbNeeded = newHSBbNeeded;
adjustForScrollLeftAndRight(hsbNeeded, availR, scrollLeftR, scrollRightR, vpbInsets);
if ((vsb != null) && !vsbNeeded &&
(vsbPolicy != VERTICAL_SCROLLBAR_NEVER)) {
extentSize = viewport.toViewCoordinates
(availR.getSize());
vsbNeeded = viewPrefSize.height >
extentSize.height;
if (vsbNeeded) {
adjustForScrollUpAndDown(true, availR, scrollUpR, scrollDownR, vpbInsets);
}
}
}
}
if (oldHSBNeeded != hsbNeeded ||
oldVSBNeeded != vsbNeeded) {
viewport.setBounds(availR);
// You could argue that we should recheck the
// Scrollable methods again until they stop changing,
// but they might never stop changing, so we stop here
// and don't do any additional checks.
}
}
}
/* We now have the final size of the viewport: availR.
* Now fixup the header and scrollbar widths/heights.
*/
// TODO
if (_scrollUp != null && _scrollDown != null) {
if (vsbNeeded) {
_scrollUp.setVisible(true);
_scrollDown.setVisible(true);
_scrollUp.setBounds(scrollUpR);
_scrollDown.setBounds(scrollDownR);
}
else {
_scrollUp.setVisible(false);
_scrollDown.setVisible(false);
_scrollUp.setBounds(scrollUpR.x, scrollUpR.y, 0, 0);
_scrollDown.setBounds(scrollDownR.x, scrollDownR.y, 0, 0);
}
}
if (_scrollLeft != null && _scrollRight != null) {
if (hsbNeeded) {
_scrollLeft.setVisible(true);
_scrollRight.setVisible(true);
_scrollLeft.setBounds(scrollLeftR);
_scrollRight.setBounds(scrollRightR);
}
else {
_scrollLeft.setVisible(false);
_scrollRight.setVisible(false);
_scrollLeft.setBounds(scrollLeftR.x, scrollLeftR.y, 0, 0);
_scrollRight.setBounds(scrollRightR.x, scrollRightR.y, 0, 0);
}
}
}
/**
* Adjusts the Rectangle available based on if
* the vertical scrollbar is needed (wantsVSB).
* The location of the vsb is updated in vsbR, and
* the viewport border insets (vpbInsets) are used to offset
* the vsb. This is only called when wantsVSB has
* changed, eg you shouldn't invoke adjustForVSB(true) twice.
*/
private void adjustForScrollUpAndDown(boolean wantsVSB, Rectangle available,
Rectangle upR, Rectangle downR, Insets vpbInsets) {
if (wantsVSB) {
int buttonWidth = Math.max(0, Math.max(available.width + vpbInsets.left + vpbInsets.right, Math.max(_scrollUp.getPreferredSize().width, _scrollDown.getPreferredSize().width)));
available.height -= upR.height;
available.height -= downR.height;
upR.width = buttonWidth;
downR.width = buttonWidth;
upR.x = available.x - vpbInsets.left;
downR.x = available.x - vpbInsets.left;
upR.y = available.y - vpbInsets.top;
available.y += upR.height;
downR.y = available.y + available.height + vpbInsets.bottom;
}
}
/**
* Adjusts the Rectangle available based on if
* the horizontal scrollbar is needed (wantsHSB).
* The location of the hsb is updated in hsbR, and
* the viewport border insets (vpbInsets) are used to offset
* the hsb. This is only called when wantsHSB has
* changed, eg you shouldn't invoked adjustForHSB(true) twice.
*/
private void adjustForScrollLeftAndRight(boolean wantsHSB, Rectangle available,
Rectangle leftR, Rectangle rightR, Insets vpbInsets) {
if (wantsHSB) {
int buttonHeight = Math.max(0, Math.max(available.height + vpbInsets.top + vpbInsets.bottom, Math.max(_scrollLeft.getPreferredSize().height, _scrollRight.getPreferredSize().height)));
available.width -= leftR.width;
available.width -= rightR.width;
leftR.height = buttonHeight;
rightR.height = buttonHeight;
leftR.y = available.y - vpbInsets.top;
rightR.y = available.y - vpbInsets.top;
leftR.x = available.x - vpbInsets.left;
available.x += leftR.width;
rightR.x = available.x + available.width + vpbInsets.right;
}
}
/**
* The UI resource version of ScrollPaneLayout.
*/
static class UIResource extends SimpleScrollPaneLayout implements javax.swing.plaf.UIResource {
}
}