|
|||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
java.lang.Objectcom.trolltech.qt.internal.QSignalEmitterInternal
com.trolltech.qt.QSignalEmitter
com.trolltech.qt.QtJambiObject
com.trolltech.qt.core.QObject
com.trolltech.qt.core.QAbstractItemModel
com.trolltech.qt.gui.QAbstractProxyModel
com.trolltech.qt.gui.QSortFilterProxyModel
public class QSortFilterProxyModel
The QSortFilterProxyModel
class provides support for sorting and filtering data passed between another model and a view. QSortFilterProxyModel
can be used for sorting items, filtering out items, or both. The model transforms the structure of a source model by mapping the model indexes it supplies to new indexes, corresponding to different locations, for views to use. This approach allows a given source model to be restructured as far as views are concerned without requiring any transformations on the underlying data, and without duplicating the data in memory.
Let's assume that we want to sort and filter the items provided by a custom model. The code to set up the model and the view, without sorting and filtering, would look like this:
QTreeView treeView = new QTreeView(); MyItemModel model = new MyItemModel(this); treeView.setModel(model);To add sorting and filtering support to MyItemModel, we need to create a
QSortFilterProxyModel
, call setSourceModel()
with the MyItemModel as argument, and install the QSortFilterProxyModel
on the view: QTreeView treeView = new QTreeView(); MyItemModel sourceModel = new MyItemModel(this); QSortFilterProxyModel proxyModel = new QSortFilterProxyModel(this); proxyModel.setSourceModel(sourceModel); treeView.setModel(proxyModel);At this point, neither sorting nor filtering is enabled; the original data is displayed in the view. Any changes made through the
QSortFilterProxyModel
are applied to the original model. The QSortFilterProxyModel
acts as a wrapper for the original model. If you need to convert source QModelIndexes to sorted/filtered model indexes or vice versa, use mapToSource()
, mapFromSource()
, mapSelectionToSource()
, and mapSelectionFromSource()
.
Note: By default, the model does not dynamically re-sort and re-filter data whenever the original model changes. This behavior can be changed by setting the dynamicSortFilter
property.
The Basic Sort/Filter Model and Custom Sort/Filter Model examples illustrate how to use QSortFilterProxyModel
to perform basic sorting and filtering and how to subclass it to implement custom behavior.Sorting
QTableView
and QTreeView
have a sortingEnabled
property that controls whether the user can sort the view by clicking the view's horizontal header. For example:
treeView.setSortingEnabled(true);When this feature is on (the default is off), clicking on a header section sorts the items according to that column. By clicking repeatedly, the user can alternate between ascending and descending order.
sort()
virtual function on the model to reorder the data in the model. To make your data sortable, you can either implement sort()
in your model, or you use a QSortFilterProxyModel
to wrap your model -- QSortFilterProxyModel
provides a generic sort()
reimplementation that operates on the sortRole()
(Qt::DisplayRole
by default) of the items and that understands several data types, including int, QString, and QDateTime
. For hierarchical models, sorting is applied recursively to all child items. String comparisons are case sensitive by default; this can be changed by setting the sortCaseSensitivity
property. Custom sorting behavior is achieved by subclassing QSortFilterProxyModel
and reimplementing lessThan()
, which is used to compare items. For example:
The following code example is written in c++.
bool MySortFilterProxyModel::lessThan(const QModelIndex &left, const QModelIndex &right) const { QVariant leftData = sourceModel()->data(left); QVariant rightData = sourceModel()->data(right); if (leftData.type() == QVariant::DateTime) { return leftData.toDateTime() < rightData.toDateTime(); } else { QRegExp *emailPattern = new QRegExp("([\\w\\.]*@[\\w\\.]*)"); QString leftString = leftData.toString(); if(left.column() == 1 && emailPattern->indexIn(leftString) != -1) leftString = emailPattern->cap(1); QString rightString = rightData.toString(); if(right.column() == 1 && emailPattern->indexIn(rightString) != -1) rightString = emailPattern->cap(1); return QString::localeAwareCompare(leftString, rightString) < 0; } }(This code snippet comes from the Custom Sort/Filter Model example.)
An alternative approach to sorting is to disable sorting on the view and to impose a certain order to the user. This is done by explicitly calling sort()
with the desired column and order as arguments on the QSortFilterProxyModel
(or on the original model if it implements sort()
). For example:
proxyModel.sort(2, Qt.SortOrder.AscendingOrder);
QSortFilterProxyModel
can be used to hide items that don't match a certain filter. The filter is specified using a QRegExp
object and is applied to the filterRole()
(Qt::DisplayRole
by default) of each item, for a given column. The QRegExp
object can be used to match a regular expression, a wildcard pattern, or a fixed string. For example: proxyModel.setFilterRegExp(new QRegExp(".png", Qt.CaseSensitivity.CaseInsensitive, QRegExp.PatternSyntax.FixedString)); proxyModel.setFilterKeyColumn(1);For hierarchical models, the filter is applied recursively to all children. If a parent item doesn't match the filter, none of its children will be shown.
A common use case is to let the user specify the filter regexp, wildcard pattern, or fixed string in a QLineEdit
and to connect the textChanged()
signal to setFilterRegExp()
, setFilterWildcard()
, or setFilterFixedString()
to reapply the filter.
Custom filtering behavior can be achieved by reimplementing the filterAcceptsRow()
and filterAcceptsColumn()
functions. For example, the following implementation ignores the filterKeyColumn
property and performs filtering on columns 0, 1, and 2:
The following code example is written in c++.
bool MySortFilterProxyModel::filterAcceptsRow(int sourceRow, const QModelIndex &sourceParent) const { QModelIndex index0 = sourceModel()->index(sourceRow, 0, sourceParent); QModelIndex index1 = sourceModel()->index(sourceRow, 1, sourceParent); QModelIndex index2 = sourceModel()->index(sourceRow, 2, sourceParent); return (sourceModel()->data(index0).toString().contains(filterRegExp()) || sourceModel()->data(index1).toString().contains(filterRegExp())) && dateInRange(sourceModel()->data(index2).toDate()); }(This code snippet comes from the Custom Sort/Filter Model example.)
If you are working with large amounts of filtering and have to invoke invalidateFilter()
repeatedly, using reset()
may be more efficient, depending on the implementation of your model. However, note that reset()
returns the proxy model to its original state, losing selection information, and will cause the proxy model to be repopulated.Subclassing
Note: Some general guidelines for subclassing models are available in the Model Subclassing Reference.
Since QAbstractProxyModel
and its subclasses are derived from QAbstractItemModel
, much of the same advice about subclassing normal models also applies to proxy models. In addition, it is worth noting that many of the default implementations of functions in this class are written so that they call the equivalent functions in the relevant source model. This simple proxying mechanism may need to be overridden for source models with more complex behavior; for example, if the source model provides a custom hasChildren()
implementation, you should also provide one in the proxy model.
QAbstractProxyModel
, QAbstractItemModel
, Model/View Programming, Basic Sort/Filter Model Example, and Custom Sort/Filter Model Example.
Nested Class Summary |
---|
Nested classes/interfaces inherited from class com.trolltech.qt.QSignalEmitter |
---|
QSignalEmitter.AbstractSignal, QSignalEmitter.Signal0, QSignalEmitter.Signal1, QSignalEmitter.Signal2, QSignalEmitter.Signal3, QSignalEmitter.Signal4, QSignalEmitter.Signal5, QSignalEmitter.Signal6, QSignalEmitter.Signal7, QSignalEmitter.Signal8, QSignalEmitter.Signal9 |
Nested classes/interfaces inherited from class com.trolltech.qt.internal.QSignalEmitterInternal |
---|
com.trolltech.qt.internal.QSignalEmitterInternal.AbstractSignalInternal |
Field Summary |
---|
Fields inherited from class com.trolltech.qt.core.QAbstractItemModel |
---|
dataChanged, headerDataChanged, layoutAboutToBeChanged, layoutChanged |
Fields inherited from class com.trolltech.qt.internal.QSignalEmitterInternal |
---|
currentSender |
Constructor Summary | |
---|---|
QSortFilterProxyModel()
Constructs a sorting filter model with the given parent. |
|
QSortFilterProxyModel(QObject parent)
Constructs a sorting filter model with the given parent. |
Method Summary | |
---|---|
boolean |
dynamicSortFilter()
This property holds whether the proxy model is dynamically sorted and filtered whenever the contents of the source model change. |
protected boolean |
filterAcceptsColumn(int source_column,
com.trolltech.qt.core.QModelIndex source_parent)
Returns true if the item in the column indicated by the given source_column and source_parent should be included in the model; otherwise returns false. |
protected boolean |
filterAcceptsRow(int source_row,
com.trolltech.qt.core.QModelIndex source_parent)
Returns true if the item in the row indicated by the given source_row and source_parent should be included in the model; otherwise returns false. |
Qt.CaseSensitivity |
filterCaseSensitivity()
This property holds the case sensitivity of the QRegExp pattern used to filter the contents of the source model. |
int |
filterKeyColumn()
This property holds the column where the key used to filter the contents of the source model is read from. |
QRegExp |
filterRegExp()
This property holds the QRegExp used to filter the contents of the source model. |
int |
filterRole()
This property holds the item role that is used to query the source model's data when filtering items. |
void |
invalidate()
Invalidates the current sorting and filtering. |
protected void |
invalidateFilter()
Invalidates the current filtering. |
boolean |
isSortLocaleAware()
This property holds the local aware setting used for comparing strings when sorting. |
protected boolean |
lessThan(com.trolltech.qt.core.QModelIndex left,
com.trolltech.qt.core.QModelIndex right)
Returns true if the value of the item referred to by the given index left is less than the value of the item referred to by the given index right, otherwise returns false. |
void |
setDynamicSortFilter(boolean enable)
This property holds whether the proxy model is dynamically sorted and filtered whenever the contents of the source model change. |
void |
setFilterCaseSensitivity(Qt.CaseSensitivity cs)
This property holds the case sensitivity of the QRegExp pattern used to filter the contents of the source model. |
void |
setFilterFixedString(java.lang.String pattern)
Sets the fixed string used to filter the contents of the source model to the given pattern. |
void |
setFilterKeyColumn(int column)
This property holds the column where the key used to filter the contents of the source model is read from. |
void |
setFilterRegExp(QRegExp regExp)
This property holds the QRegExp used to filter the contents of the source model. |
void |
setFilterRegExp(java.lang.String pattern)
This property holds the QRegExp used to filter the contents of the source model. |
void |
setFilterRole(int role)
This property holds the item role that is used to query the source model's data when filtering items. |
void |
setFilterWildcard(java.lang.String pattern)
Sets the wildcard expression used to filter the contents of the source model to the given pattern. |
void |
setSortCaseSensitivity(Qt.CaseSensitivity cs)
This property holds the case sensitivity setting used for comparing strings when sorting. |
void |
setSortLocaleAware(boolean on)
This property holds the local aware setting used for comparing strings when sorting. |
void |
setSortRole(int role)
This property holds the item role that is used to query the source model's data when sorting items. |
Qt.CaseSensitivity |
sortCaseSensitivity()
This property holds the case sensitivity setting used for comparing strings when sorting. |
int |
sortRole()
This property holds the item role that is used to query the source model's data when sorting items. |
Methods inherited from class com.trolltech.qt.gui.QAbstractProxyModel |
---|
mapFromSource, mapSelectionFromSource, mapSelectionToSource, mapToSource, setSourceModel, sourceModel |
Methods inherited from class com.trolltech.qt.core.QObject |
---|
childEvent, children, connectSlotsByName, customEvent, disposeLater, dumpObjectInfo, dumpObjectTree, dynamicPropertyNames, event, eventFilter, findChild, findChild, findChild, findChildren, findChildren, findChildren, findChildren, indexOfProperty, installEventFilter, isWidgetType, killTimer, moveToThread, objectName, parent, properties, property, removeEventFilter, setObjectName, setParent, setProperty, startTimer, timerEvent, toString, userProperty |
Methods inherited from class com.trolltech.qt.QtJambiObject |
---|
dispose, disposed, equals, finalize, reassignNativeResources, tr, tr, tr |
Methods inherited from class com.trolltech.qt.QSignalEmitter |
---|
blockSignals, disconnect, disconnect, signalsBlocked, signalSender, thread |
Methods inherited from class com.trolltech.qt.internal.QSignalEmitterInternal |
---|
__qt_signalInitialization |
Methods inherited from class java.lang.Object |
---|
clone, getClass, hashCode, notify, notifyAll, wait, wait, wait |
Methods inherited from interface com.trolltech.qt.QtJambiInterface |
---|
disableGarbageCollection, nativeId, nativePointer, reenableGarbageCollection, setJavaOwnership |
Constructor Detail |
---|
public QSortFilterProxyModel()
public QSortFilterProxyModel(QObject parent)
Method Detail |
---|
public final boolean dynamicSortFilter()
public final Qt.CaseSensitivity filterCaseSensitivity()
QRegExp
pattern used to filter the contents of the source model. By default, the filter is case sensitive. filterRegExp
, and sortCaseSensitivity
.
public final int filterKeyColumn()
public final QRegExp filterRegExp()
QRegExp
used to filter the contents of the source model. Setting this property overwrites the current filterCaseSensitivity
. By default, the QRegExp
is an empty string matching all contents. filterCaseSensitivity
, setFilterWildcard()
, and setFilterFixedString()
.
public final int filterRole()
Qt::DisplayRole
. filterAcceptsRow()
.
public final void invalidate()
invalidateFilter()
.
protected final void invalidateFilter()
This function should be called if you are implementing custom filtering (e.g. filterAcceptsRow()
), and your filter parameters have changed.
invalidate()
.
public final boolean isSortLocaleAware()
sortCaseSensitivity
, and lessThan()
.
public final void setDynamicSortFilter(boolean enable)
public final void setFilterCaseSensitivity(Qt.CaseSensitivity cs)
QRegExp
pattern used to filter the contents of the source model. By default, the filter is case sensitive. filterRegExp
, and sortCaseSensitivity
.
public final void setFilterFixedString(java.lang.String pattern)
setFilterCaseSensitivity()
, setFilterRegExp()
, setFilterWildcard()
, and filterRegExp()
.
public final void setFilterKeyColumn(int column)
public final void setFilterRegExp(QRegExp regExp)
QRegExp
used to filter the contents of the source model. Setting this property overwrites the current filterCaseSensitivity
. By default, the QRegExp
is an empty string matching all contents. filterCaseSensitivity
, setFilterWildcard()
, and setFilterFixedString()
.
public final void setFilterRegExp(java.lang.String pattern)
QRegExp
used to filter the contents of the source model. Setting this property overwrites the current filterCaseSensitivity
. By default, the QRegExp
is an empty string matching all contents. filterCaseSensitivity
, setFilterWildcard()
, and setFilterFixedString()
.
public final void setFilterRole(int role)
Qt::DisplayRole
. filterAcceptsRow()
.
public final void setFilterWildcard(java.lang.String pattern)
setFilterCaseSensitivity()
, setFilterRegExp()
, setFilterFixedString()
, and filterRegExp()
.
public final void setSortCaseSensitivity(Qt.CaseSensitivity cs)
filterCaseSensitivity
, and lessThan()
.
public final void setSortLocaleAware(boolean on)
sortCaseSensitivity
, and lessThan()
.
public final void setSortRole(int role)
Qt::DisplayRole
. lessThan()
.
public final Qt.CaseSensitivity sortCaseSensitivity()
filterCaseSensitivity
, and lessThan()
.
public final int sortRole()
Qt::DisplayRole
. lessThan()
.
protected boolean filterAcceptsColumn(int source_column, com.trolltech.qt.core.QModelIndex source_parent)
The default implementation returns true if the value held by the relevant item matches the filter string, wildcard string or regular expression.
Note: By default, the Qt::DisplayRole
is used to determine if the row should be accepted or not. This can be changed by setting the filterRole
property.
filterAcceptsRow()
, setFilterFixedString()
, setFilterRegExp()
, and setFilterWildcard()
.
protected boolean filterAcceptsRow(int source_row, com.trolltech.qt.core.QModelIndex source_parent)
The default implementation returns true if the value held by the relevant item matches the filter string, wildcard string or regular expression.
Note: By default, the Qt::DisplayRole
is used to determine if the row should be accepted or not. This can be changed by setting the filterRole
property.
filterAcceptsColumn()
, setFilterFixedString()
, setFilterRegExp()
, and setFilterWildcard()
.
protected boolean lessThan(com.trolltech.qt.core.QModelIndex left, com.trolltech.qt.core.QModelIndex right)
This function is used as the < operator when sorting, and handles the following QVariant
types:
QVariant::Int
QVariant::UInt
QVariant::LongLong
QVariant::ULongLong
QVariant::Double
QVariant::Char
QVariant::Date
QVariant::Time
QVariant::DateTime
QVariant::String
QVariant::toString()
. Comparison of QStrings is case sensitive by default; this can be changed using the sortCaseSensitivity
property.
By default, the Qt::DisplayRole
associated with the QModelIndexes is used for comparisons. This can be changed by setting the sortRole
property.
Note: The indices passed in correspond to the source model.
sortRole
, sortCaseSensitivity
, and dynamicSortFilter
.
|
|||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |