QDataWidgetMapper¶
The
QDataWidgetMapper
class provides mapping between a section of a data model to widgets. More…
Synopsis¶
Functions¶
def
addMapping
(widget, section)def
addMapping
(widget, section, propertyName)def
clearMapping
()def
currentIndex
()def
itemDelegate
()def
mappedPropertyName
(widget)def
mappedSection
(widget)def
mappedWidgetAt
(section)def
model
()def
orientation
()def
removeMapping
(widget)def
rootIndex
()def
setItemDelegate
(delegate)def
setModel
(model)def
setOrientation
(aOrientation)def
setRootIndex
(index)def
setSubmitPolicy
(policy)def
submitPolicy
()
Virtual functions¶
def
setCurrentIndex
(index)
Slots¶
def
revert
()def
setCurrentModelIndex
(index)def
submit
()def
toFirst
()def
toLast
()def
toNext
()def
toPrevious
()
Signals¶
def
currentIndexChanged
(index)
Detailed Description¶
QDataWidgetMapper
can be used to create data-aware widgets by mapping them to sections of an item model. A section is a column of a model if the orientation is horizontal (the default), otherwise a row.Every time the current index changes, each widget is updated with data from the model via the property specified when its mapping was made. If the user edits the contents of a widget, the changes are read using the same property and written back to the model. By default, each widget’s
user property
is used to transfer data between the model and the widget. Since Qt 4.3, an additionaladdMapping()
function enables a named property to be used instead of the default user property.It is possible to set an item delegate to support custom widgets. By default, a
QItemDelegate
is used to synchronize the model with the widgets.Let us assume that we have an item model named
model
with the following contents:
1
Qt Norway
Oslo
2
Qt Australia
Brisbane
3
Qt USA
Palo Alto
4
Qt China
Beijing
5
Qt Germany
Berlin
The following code will map the columns of the model to widgets called
mySpinBox
,myLineEdit
andmyCountryChooser
:mapper = QDataWidgetMapper mapper.setModel(model) mapper.addMapping(mySpinBox, 0) mapper.addMapping(myLineEdit, 1) mapper.addMapping(myCountryChooser, 2) mapper.toFirst()After the call to
toFirst()
,mySpinBox
displays the value1
,myLineEdit
displaysQt Norway
andmyCountryChooser
displaysOslo
. The navigational functionstoFirst()
,toNext()
,toPrevious()
,toLast()
andsetCurrentIndex()
can be used to navigate in the model and update the widgets with contents from the model.The
setRootIndex()
function enables a particular item in a model to be specified as the root index - children of this item will be mapped to the relevant widgets in the user interface.
QDataWidgetMapper
supports two submit policies,AutoSubmit
andManualSubmit
.AutoSubmit
will update the model as soon as the current widget loses focus,ManualSubmit
will not update the model unlesssubmit()
is called.ManualSubmit
is useful when displaying a dialog that lets the user cancel all modifications. Also, other views that display the model won’t update until the user finishes all their modifications and submits.Note that
QDataWidgetMapper
keeps track of external modifications. If the contents of the model are updated in another module of the application, the widgets are updated as well.See also
QAbstractItemModel
QAbstractItemDelegate
- class PySide2.QtWidgets.QDataWidgetMapper([parent=None])¶
- param parent:
Constructs a new
QDataWidgetMapper
with parent objectparent
. By default, the orientation is horizontal and the submit policy isAutoSubmit
.See also
- PySide2.QtWidgets.QDataWidgetMapper.SubmitPolicy¶
This enum describes the possible submit policies a
QDataWidgetMapper
supports.Constant
Description
QDataWidgetMapper.AutoSubmit
Whenever a widget loses focus, the widget’s current value is set to the item model.
QDataWidgetMapper.ManualSubmit
The model is not updated until
submit()
is called.
- PySide2.QtWidgets.QDataWidgetMapper.addMapping(widget, section)¶
- Parameters:
widget –
PySide2.QtWidgets.QWidget
section – int
Adds a mapping between a
widget
and asection
from the model. Thesection
is a column in the model if the orientation is horizontal (the default), otherwise a row.For the following example, we assume a model
myModel
that has two columns: the first one contains the names of people in a group, and the second column contains their ages. The first column is mapped to theQLineEdit
nameLineEdit
, and the second is mapped to theQSpinBox
ageSpinBox
:mapper = QDataWidgetMapper() mapper.setModel(myModel) mapper.addMapping(nameLineEdit, 0) mapper.addMapping(ageSpinBox, 1)
Notes:
If the
widget
is already mapped to a section, the old mapping will be replaced by the new one.Only one-to-one mappings between sections and widgets are allowed. It is not possible to map a single section to multiple widgets, or to map a single widget to multiple sections.
See also
- PySide2.QtWidgets.QDataWidgetMapper.addMapping(widget, section, propertyName)
- Parameters:
widget –
PySide2.QtWidgets.QWidget
section – int
propertyName –
PySide2.QtCore.QByteArray
Essentially the same as
addMapping()
, but adds the possibility to specify the property to use specifyingpropertyName
.See also
- PySide2.QtWidgets.QDataWidgetMapper.clearMapping()¶
Clears all mappings.
See also
- PySide2.QtWidgets.QDataWidgetMapper.currentIndex()¶
- Return type:
int
This property holds the current row or column.
The widgets are populated with with data from the row at
index
if the orientation is horizontal (the default), otherwise with data from the column atindex
.
- PySide2.QtWidgets.QDataWidgetMapper.currentIndexChanged(index)¶
- Parameters:
index – int
- PySide2.QtWidgets.QDataWidgetMapper.itemDelegate()¶
- Return type:
Returns the current item delegate.
See also
- PySide2.QtWidgets.QDataWidgetMapper.mappedPropertyName(widget)¶
- Parameters:
widget –
PySide2.QtWidgets.QWidget
- Return type:
Returns the name of the property that is used when mapping data to the given
widget
.See also
- PySide2.QtWidgets.QDataWidgetMapper.mappedSection(widget)¶
- Parameters:
widget –
PySide2.QtWidgets.QWidget
- Return type:
int
Returns the section the
widget
is mapped to or -1 if the widget is not mapped.See also
- PySide2.QtWidgets.QDataWidgetMapper.mappedWidgetAt(section)¶
- Parameters:
section – int
- Return type:
Returns the widget that is mapped at
section
, or 0 if no widget is mapped at that section.See also
- PySide2.QtWidgets.QDataWidgetMapper.model()¶
- Return type:
Returns the current model.
See also
- PySide2.QtWidgets.QDataWidgetMapper.orientation()¶
- Return type:
This property holds the orientation of the model.
If the orientation is
Horizontal
(the default), a widget is mapped to a column of a data model. The widget will be populated with the model’s data from its mapped column and the row thatcurrentIndex()
points at.Use
Horizontal
for tabular data that looks like this:1
Qt Norway
Oslo
2
Qt Australia
Brisbane
3
Qt USA
Silicon Valley
4
Qt China
Beijing
5
Qt Germany
Berlin
If the orientation is set to
Vertical
, a widget is mapped to a row. CallingsetCurrentIndex()
will change the current column. The widget will be populates with the model’s data from its mapped row and the column thatcurrentIndex()
points at.Use
Vertical
for tabular data that looks like this:1
2
3
4
5
Qt Norway
Qt Australia
Qt USA
Qt China
Qt Germany
Oslo
Brisbane
Silicon Valley
Beijing
Berlin
Changing the orientation clears all existing mappings.
- PySide2.QtWidgets.QDataWidgetMapper.removeMapping(widget)¶
- Parameters:
widget –
PySide2.QtWidgets.QWidget
Removes the mapping for the given
widget
.See also
- PySide2.QtWidgets.QDataWidgetMapper.revert()¶
Repopulates all widgets with the current data of the model. All unsubmitted changes will be lost.
See also
- PySide2.QtWidgets.QDataWidgetMapper.rootIndex()¶
- Return type:
Returns the current root index.
See also
- PySide2.QtWidgets.QDataWidgetMapper.setCurrentIndex(index)¶
- Parameters:
index – int
This property holds the current row or column.
The widgets are populated with with data from the row at
index
if the orientation is horizontal (the default), otherwise with data from the column atindex
.
- PySide2.QtWidgets.QDataWidgetMapper.setCurrentModelIndex(index)¶
- Parameters:
index –
PySide2.QtCore.QModelIndex
Sets the current index to the row of the
index
if the orientation is horizontal (the default), otherwise to the column of theindex
.Calls
setCurrentIndex()
internally. This convenience slot can be connected to the signalcurrentRowChanged()
orcurrentColumnChanged()
of another view’sselection model
.The following example illustrates how to update all widgets with new data whenever the selection of a
QTableView
namedmyTableView
changes:mapper = QDataWidgetMapper() connect(myTableView.selectionModel(), SIGNAL("currentRowChanged(QModelIndex,QModelIndex)"), mapper, SLOT(setCurrentModelIndex(QModelIndex)))
See also
- PySide2.QtWidgets.QDataWidgetMapper.setItemDelegate(delegate)¶
- Parameters:
delegate –
PySide2.QtWidgets.QAbstractItemDelegate
Sets the item delegate to
delegate
. The delegate will be used to write data from the model into the widget and from the widget to the model, usingsetEditorData()
andsetModelData()
.The delegate also decides when to apply data and when to change the editor, using
commitData()
andcloseEditor()
.Warning
You should not share the same instance of a delegate between widget mappers or views. Doing so can cause incorrect or unintuitive editing behavior since each view connected to a given delegate may receive the
closeEditor()
signal, and attempt to access, modify or close an editor that has already been closed.See also
- PySide2.QtWidgets.QDataWidgetMapper.setModel(model)¶
- Parameters:
Sets the current model to
model
. If another model was set, all mappings to that old model are cleared.See also
- PySide2.QtWidgets.QDataWidgetMapper.setOrientation(aOrientation)¶
- Parameters:
aOrientation –
Orientation
This property holds the orientation of the model.
If the orientation is
Horizontal
(the default), a widget is mapped to a column of a data model. The widget will be populated with the model’s data from its mapped column and the row thatcurrentIndex()
points at.Use
Horizontal
for tabular data that looks like this:1
Qt Norway
Oslo
2
Qt Australia
Brisbane
3
Qt USA
Silicon Valley
4
Qt China
Beijing
5
Qt Germany
Berlin
If the orientation is set to
Vertical
, a widget is mapped to a row. CallingsetCurrentIndex()
will change the current column. The widget will be populates with the model’s data from its mapped row and the column thatcurrentIndex()
points at.Use
Vertical
for tabular data that looks like this:1
2
3
4
5
Qt Norway
Qt Australia
Qt USA
Qt China
Qt Germany
Oslo
Brisbane
Silicon Valley
Beijing
Berlin
Changing the orientation clears all existing mappings.
- PySide2.QtWidgets.QDataWidgetMapper.setRootIndex(index)¶
- Parameters:
index –
PySide2.QtCore.QModelIndex
Sets the root item to
index
. This can be used to display a branch of a tree. Pass an invalid model index to display the top-most branch.See also
- PySide2.QtWidgets.QDataWidgetMapper.setSubmitPolicy(policy)¶
- Parameters:
policy –
SubmitPolicy
This property holds the current submit policy.
Changing the current submit policy will revert all widgets to the current data from the model.
- PySide2.QtWidgets.QDataWidgetMapper.submit()¶
- Return type:
bool
Submits all changes from the mapped widgets to the model.
For every mapped section, the item delegate reads the current value from the widget and sets it in the model. Finally, the model’s
submit()
method is invoked.Returns
true
if all the values were submitted, otherwise false.Note: For database models,
lastError()
can be used to retrieve the last error.See also
- PySide2.QtWidgets.QDataWidgetMapper.submitPolicy()¶
- Return type:
This property holds the current submit policy.
Changing the current submit policy will revert all widgets to the current data from the model.
- PySide2.QtWidgets.QDataWidgetMapper.toFirst()¶
Populates the widgets with data from the first row of the model if the orientation is horizontal (the default), otherwise with data from the first column.
This is equivalent to calling
setCurrentIndex(0)
.See also
- PySide2.QtWidgets.QDataWidgetMapper.toLast()¶
Populates the widgets with data from the last row of the model if the orientation is horizontal (the default), otherwise with data from the last column.
Calls
setCurrentIndex()
internally.See also
- PySide2.QtWidgets.QDataWidgetMapper.toNext()¶
Populates the widgets with data from the next row of the model if the orientation is horizontal (the default), otherwise with data from the next column.
Calls
setCurrentIndex()
internally. Does nothing if there is no next row in the model.See also
- PySide2.QtWidgets.QDataWidgetMapper.toPrevious()¶
Populates the widgets with data from the previous row of the model if the orientation is horizontal (the default), otherwise with data from the previous column.
Calls
setCurrentIndex()
internally. Does nothing if there is no previous row in the model.See also
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