zul/src/main/java/org/zkoss/zul/impl/GridDataLoader.java
/* GridDataLoader.java
{{IS_NOTE
Purpose:
Description:
History:
Oct 29, 2009 10:44:57 AM, Created by henrichen
}}IS_NOTE
Copyright (C) 2009 Potix Corporation. All Rights Reserved.
{{IS_RIGHT
This program is distributed under GPL Version 3.0 in the hope that
it will be useful, but WITHOUT ANY WARRANTY.
}}IS_RIGHT
*/
package org.zkoss.zul.impl;
import java.util.LinkedHashSet;
import java.util.Set;
import org.zkoss.lang.Objects;
import org.zkoss.xel.VariableResolver;
import org.zkoss.zk.ui.Component;
import org.zkoss.zk.ui.UiException;
import org.zkoss.zk.ui.ext.render.Cropper;
import org.zkoss.zk.ui.sys.ShadowElementsCtrl;
import org.zkoss.zk.ui.util.ForEachStatus;
import org.zkoss.zk.ui.util.Template;
import org.zkoss.zul.Attributes;
import org.zkoss.zul.Grid;
import org.zkoss.zul.Group;
import org.zkoss.zul.GroupRendererExt;
import org.zkoss.zul.Groupfoot;
import org.zkoss.zul.Label;
import org.zkoss.zul.ListModel;
import org.zkoss.zul.Row;
import org.zkoss.zul.RowRenderer;
import org.zkoss.zul.RowRendererExt;
import org.zkoss.zul.Rows;
import org.zkoss.zul.event.GroupsDataEvent;
import org.zkoss.zul.event.ListDataEvent;
import org.zkoss.zul.ext.GroupingInfo;
import org.zkoss.zul.ext.Paginal;
import org.zkoss.zul.impl.GroupsListModel.GroupDataInfo;
/**
* Generic {@link Grid} data loader.
* @author henrichen
* @since 5.0.0
*/
public class GridDataLoader implements DataLoader, Cropper {
private Grid _grid;
//--DataLoader--//
public void init(Component owner, int offset, int limit) {
_grid = (Grid) owner;
}
public void reset() {
//do nothing
}
public final Component getOwner() {
return _grid;
}
public int getOffset() {
return 0;
}
public int getLimit() {
return 50;
}
public int getTotalSize() {
final Rows rows = _grid.getRows();
final ListModel model = _grid.getModel();
return model != null ? model.getSize() : rows != null ? rows.getVisibleItemCount() : 0;
}
private int INVALIDATE_THRESHOLD = -1;
public void doGroupsDataChange(GroupsDataEvent event) {
if (event.getType() == GroupsDataEvent.GROUPS_OPENED) {
GroupsListModel groupsListModel = ((GroupsListModel) _grid.getModel());
int groupIndex = event.getGroupIndex();
int offset = groupsListModel.getGroupOffset(groupIndex);
((Group) _grid.getRows().getChildren().get(offset)).setOpen(event.getModel().isGroupOpened(groupIndex));
}
}
public void doListDataChange(ListDataEvent event) {
if (INVALIDATE_THRESHOLD == -1) {
INVALIDATE_THRESHOLD = Utils.getIntAttribute(this.getOwner(), "org.zkoss.zul.invalidateThreshold", 10,
true);
}
//when this is called _model is never null
final Rows rows = _grid.getRows();
final int newsz = event.getModel().getSize(), oldsz = rows.getChildren().size();
int min = event.getIndex0(), max = event.getIndex1(), cnt;
switch (event.getType()) {
case ListDataEvent.INTERVAL_ADDED:
cnt = newsz - oldsz;
if (cnt <= 0) {
syncModel(-1, -1); //out of sync, force sync
return;
//throw new UiException("Adding causes a smaller list?");
}
if ((oldsz <= 0 || cnt > INVALIDATE_THRESHOLD) && !inPagingMold())
rows.invalidate();
//Invalidate rows to improve the performance since it is faster
//to remove a lot of individual rows. It is safer than invalidating
//the whole grid since header might have an input affecting the model
//(e.g., ZK-985: demo's data filter)
//The memory leak of IE is better with outer (Bug 3147518),
//and even better with _grid.invalidate() but better to solve ZK-985
if (min < 0)
if (max < 0)
min = 0;
else
min = max - cnt + 1;
if (min > oldsz)
min = oldsz;
RowRenderer renderer = null;
final Component next = min < oldsz ? rows.getChildren().get(min) : null;
while (--cnt >= 0) {
if (renderer == null)
renderer = (RowRenderer) getRealRenderer();
rows.insertBefore(newUnloadedItem(renderer, min++), next);
}
// Fix ZK-5468: the content of the subsequence item might be changed
if (!rows.isInvalidated()) {
syncModel(max, rows.getChildren().size() - (max - min));
}
break;
case ListDataEvent.INTERVAL_REMOVED:
cnt = oldsz - newsz;
if (cnt <= 0) {
syncModel(-1, -1); //out of sync, force sync
return;
//throw new UiException("Removal causes a larger list?");
}
if ((newsz <= 0 || cnt > INVALIDATE_THRESHOLD) && !inPagingMold())
rows.invalidate();
//Invalidate rows to improve the performance see above
if (min >= 0)
max = min + cnt - 1;
else if (max < 0)
max = cnt - 1; //0 ~ cnt - 1
if (max > oldsz - 1)
max = oldsz - 1;
//detach from end (due to groupfoot issue)
Component comp = rows.getChildren().get(max);
while (--cnt >= 0) {
Component p = comp.getPreviousSibling();
comp.detach();
comp = p;
}
// Fix ZK-5468: the content of the subsequence item might be changed
if (!rows.isInvalidated()) {
syncModel(max, rows.getChildren().size() - (max - min));
}
break;
default: //CONTENTS_CHANGED
syncModel(min, max < 0 ? -1 : (max - min + 1));
}
}
/** Creates a new and unloaded row. */
protected Component newUnloadedItem(Object renderer, int index) {
final RowRenderer renderer0 = (RowRenderer) renderer;
final ListModel model = ((Grid) getOwner()).getModel();
Row row = null;
if (model instanceof GroupsListModel) {
final GroupsListModel gmodel = (GroupsListModel) model;
final GroupingInfo info = gmodel.getDataInfo(index);
switch (info.getType()) {
case GroupDataInfo.GROUP:
row = newGroup(renderer0);
((Group) row).setOpen(info.isOpen());
break;
case GroupDataInfo.GROUPFOOT:
row = newGroupfoot(renderer0);
break;
default:
row = newRow(renderer0);
}
} else {
row = newRow(renderer0);
}
((LoadStatus) row.getExtraCtrl()).setLoaded(false);
((LoadStatus) row.getExtraCtrl()).setIndex(index);
newUnloadedCell(renderer0, row);
return row;
}
private Row newRow(RowRenderer renderer) {
Row row = null;
if (renderer instanceof RowRendererExt)
row = ((RowRendererExt) renderer).newRow((Grid) getOwner());
if (row == null) {
row = new Row();
row.applyProperties();
}
return row;
}
private Group newGroup(RowRenderer renderer) {
Group group = null;
if (renderer instanceof GroupRendererExt)
group = ((GroupRendererExt) renderer).newGroup((Grid) getOwner());
if (group == null) {
group = new Group();
group.applyProperties();
}
return group;
}
private Groupfoot newGroupfoot(RowRenderer renderer) {
Groupfoot groupfoot = null;
if (renderer instanceof GroupRendererExt)
groupfoot = ((GroupRendererExt) renderer).newGroupfoot((Grid) getOwner());
if (groupfoot == null) {
groupfoot = new Groupfoot();
groupfoot.applyProperties();
}
return groupfoot;
}
private Component newUnloadedCell(RowRenderer renderer, Row row) {
Component cell = null;
if (renderer instanceof RowRendererExt)
cell = ((RowRendererExt) renderer).newCell(row);
if (cell == null) {
cell = newRenderLabel(null);
cell.applyProperties();
}
cell.setParent(row);
return cell;
}
/** Returns the label for the cell generated by the default renderer.
*/
private static Label newRenderLabel(String value) {
final Label label = new Label(value != null && value.length() > 0 ? value : " ");
label.setPre(true); //to make sure is generated, and then occupies some space
return label;
}
public Object getRealRenderer() {
final RowRenderer renderer = _grid.getRowRenderer();
return renderer != null ? renderer : _defRend;
}
private static final RowRenderer _defRend = new RowRenderer() {
public void render(final Row row, final Object data, final int index) {
final Rows rows = (Rows) row.getParent();
final Grid grid = (Grid) rows.getParent();
Template tm = getTemplate(grid, rows, "model");
GroupingInfo info = null;
if (row instanceof Group) {
final Template tm2 = getTemplate(grid, rows, "model:group");
if (tm2 != null)
tm = tm2;
if (grid.getModel() instanceof GroupsListModel) {
final GroupsListModel gmodel = (GroupsListModel) grid.getModel();
info = gmodel.getDataInfo(index);
}
} else if (row instanceof Groupfoot) {
final Template tm2 = getTemplate(grid, rows, "model:groupfoot");
if (tm2 != null)
tm = tm2;
}
if (tm == null) {
final Label label = newRenderLabel(Objects.toString(data));
label.applyProperties();
label.setParent(row);
row.setValue(data);
} else {
final GroupingInfo groupingInfo = info;
final Component[] items = ShadowElementsCtrl
.filterOutShadows(tm.create(rows, row, new VariableResolver() {
public Object resolveVariable(String name) {
if ("each".equals(name)) {
return data;
} else if ("forEachStatus".equals(name)) {
return new ForEachStatus() {
public ForEachStatus getPrevious() {
return null;
}
public Object getEach() {
return getCurrent();
}
public int getIndex() {
return index;
}
public Integer getBegin() {
return 0;
}
public Integer getEnd() {
return grid.getModel().getSize();
}
public Object getCurrent() {
return data;
}
public boolean isFirst() {
return getCount() == 1;
}
public boolean isLast() {
return getIndex() + 1 == getEnd();
}
public Integer getStep() {
return null;
}
public int getCount() {
return getIndex() + 1;
}
};
} else if ("groupingInfo".equals(name)) {
return groupingInfo;
} else {
return null;
}
}
}, null));
if (items.length != 1)
throw new UiException("The model template must have exactly one row, not " + items.length);
final Row nr = (Row) items[0];
//sync open state
if (nr instanceof Group && row instanceof Group) {
((Group) nr).setOpen(((Group) row).isOpen());
}
if (nr.getValue() == null) //template might set it
nr.setValue(data);
row.setAttribute(Attributes.MODEL_RENDERAS, nr);
//indicate a new row is created to replace the existent one
row.detach();
}
}
};
private static Template getTemplate(Grid grid, Rows rows, String name) {
final Template tm = grid.getTemplate(name);
return tm != null ? tm : rows != null ? rows.getTemplate(name) : null;
// Also allow model's template to be declared in Rows
}
public void syncModel(int offset, int limit) {
int min = offset;
int max = offset + limit - 1;
final ListModel model = _grid.getModel();
Rows rows = _grid.getRows();
final int newsz = model.getSize();
final int oldsz = rows != null ? rows.getChildren().size() : 0;
final Paginal pgi = _grid.getPaginal();
final boolean inPaging = inPagingMold();
final boolean shallInvalidated = //Bug 3147518: avoid memory leak
(min < 0 || min == 0) && (max < 0 || max >= newsz || max >= oldsz);
int newcnt = newsz - oldsz;
int atg = pgi != null ? _grid.getActivePage() : 0;
RowRenderer renderer = null;
Component next = null;
if (oldsz > 0) {
if (min < 0)
min = 0;
else if (min > oldsz - 1)
min = oldsz - 1;
if (max < 0)
max = oldsz - 1;
else if (max > oldsz - 1)
max = oldsz - 1;
if (min > max) {
int t = min;
min = max;
max = t;
}
int cnt = max - min + 1; //# of affected
if (rows != null) {
if (model instanceof GroupsListModel) {
//detach all from end to front since groupfoot
//must be detached before group
newcnt += cnt; //add affected later
if ((shallInvalidated || newcnt > INVALIDATE_THRESHOLD) && !inPaging)
rows.invalidate();
//Invalidate rows to improve the performance see above
Component comp = rows.getChildren().get(max);
next = comp.getNextSibling();
while (--cnt >= 0) {
Component p = comp.getPreviousSibling();
comp.detach();
comp = p;
}
} else { //ListModel
int addcnt = 0;
Component row = rows.getChildren().get(min);
while (--cnt >= 0) {
next = row.getNextSibling();
if (cnt < -newcnt) { //if shrink, -newcnt > 0
row.detach(); //remove extra
} else if (((LoadStatus) ((Row) row).getExtraCtrl()).isLoaded()) {
if (renderer == null)
renderer = (RowRenderer) getRealRenderer();
row.detach(); //always detach
rows.insertBefore(newUnloadedItem(renderer, min), next);
++addcnt;
}
++min;
row = next;
}
if ((shallInvalidated || addcnt > INVALIDATE_THRESHOLD || addcnt + newcnt > INVALIDATE_THRESHOLD)
&& !inPaging)
rows.invalidate();
//Invalidate rows to improve the performance see above
}
}
} else {
min = 0;
//auto create but it means <grid model="xx"><rows/>... will fail
if (rows == null) {
rows = new Rows();
rows.setParent(_grid);
}
}
for (; --newcnt >= 0; ++min) {
if (renderer == null)
renderer = (RowRenderer) getRealRenderer();
rows.insertBefore(newUnloadedItem(renderer, min), next);
}
if (pgi != null) {
if (atg >= pgi.getPageCount())
atg = pgi.getPageCount() - 1;
pgi.setActivePage(atg);
if (pgi.getTotalSize() != newsz)
pgi.setTotalSize(newsz); //Bug ZK-1888 - Grid in paging mold doesn't change pages count
}
}
protected boolean inPagingMold() {
return "paging".equals(_grid.getMold());
}
public void updateModelInfo() {
// do nothing
}
public void setLoadAll(boolean b) {
//do nothing
}
//--Cropper--//
public boolean isCropper() {
return _grid != null && inPagingMold() && _grid.getPageSize() <= getTotalSize();
//Single page is considered as not a cropper.
//isCropper is called after a component is removed, so
//we have to test >= rather than >
}
public Set<? extends Component> getAvailableAtClient() {
if (!isCropper())
return null;
final Paginal pgi = _grid.getPaginal();
int pgsz = pgi.getPageSize();
int ofs = pgi.getActivePage() * pgsz;
return getAvailableAtClient(ofs, pgsz);
}
protected Set<? extends Component> getAvailableAtClient(int offset, int limit) {
final Set<Component> avail = new LinkedHashSet<Component>(32);
final Rows rows = _grid.getRows();
Row row = (Row) rows.getFirstChild();
while (row != null) {
if (limit == 0)
break;
if (row.isVisible()) {
if (--offset < 0) {
--limit;
avail.add(row);
}
}
if (row instanceof Group) {
final Group g = (Group) row;
if (!g.isOpen()) {
for (int j = 0, len = g.getItemCount(); j < len && row != null; j++)
row = (Row) row.getNextSibling();
}
}
if (row != null)
row = (Row) row.getNextSibling();
}
return avail;
}
public Component getCropOwner() {
return _grid;
}
}