Closes #70: add methods to remove widgets from forms (#93)

- Adds method to remove widgets from forms.
- Adds method to extract the number of widgets from forms.
- Adds `addSpanningWidget` method to `FormDockWidget`.
- Adds example to remove widgets from the `FormDialog` and the `FormDockWidget`.
- Adds the unit test for the removal of widgets from the forms.

eqt/ui/FormDialog.py

@@ -74,6 +74,14 @@ def addWidget(self, qwidget, qlabel=None, name=None, layout='form'):
         else:
             raise ValueError(f"layout '{layout}' unrecognised: expected 'form' or 'vertical'")
 
+    def removeWidget(self, name):
+        '''
+        Removes a widget (and its label if present) from the layout.
+        Decreases the counter for the number of widgets in the layout.
+        Deletes the field (and label) from the dictionary.
+        '''
+        self.formWidget.removeWidget(name)
+
     def addSpanningWidget(self, qwidget, name=None, layout='form'):
         '''
         Adds a spanning widget to the layout.
@@ -93,6 +101,12 @@ def addSpanningWidget(self, qwidget, name=None, layout='form'):
             raise ValueError(
                 f"layout {layout} is not recognised, must be set to 'form' or 'vertical'")
 
+    def getNumWidgets(self):
+        '''
+        Returns the number of widgets in the form.
+        '''
+        return self.formWidget.getNumWidgets()
+
     def insertWidget(self, index, qwidget):
         '''inserts a widget to the vertical layout at the specific index'''
         self.formWidget.uiElements['verticalLayout'].insertWidget(index, qwidget)

eqt/ui/UIFormWidget.py

@@ -1,3 +1,5 @@
+import logging
+
 from PySide2 import QtWidgets
 
 from .UISliderWidget import UISliderWidget
@@ -55,6 +57,28 @@ def addSpanningWidget(self, qwidget, name):
     def addWidget(self, qwidget, qlabel, name):
         self._addWidget(name, qwidget, qlabel)
 
+    def removeWidget(self, name):
+        '''
+        Removes a widget (and its label if present) from the layout.
+        Decreases the counter for the number of widgets in the layout.
+        Deletes the field (and label) from the dictionary.
+        '''
+        formLayout = self.uiElements['groupBoxFormLayout']
+        qwidget = self.getWidget(name, role='field') # retrieves the widget from its name
+        formLayout.removeRow(qwidget)                # removes the whole row from the layout
+        self.num_widgets -= 1                        # updates total number of widgets
+        self.getWidgets().pop(name + '_field')       # removes field from the dictionary
+        try:
+            self.getWidgets().pop(name + '_label')
+        except KeyError:
+            logging.info('Widget ' + name + ' does not have a label.')
+
+    def getNumWidgets(self):
+        '''
+        Returns the number of widgets in the form.
+        '''
+        return self.num_widgets
+
     def getWidget(self, name, role='field'):
         '''returns the Widget by the name with which it has been added
 
@@ -322,6 +346,23 @@ def __init__(self, parent=None, title=None):
     def addWidget(self, qwidget, qlabel, name):
         self.widget().addWidget(qwidget, qlabel, name)
 
+    def addSpanningWidget(self, qwidget, name):
+        self.widget().addSpanningWidget(qwidget, name)
+
+    def removeWidget(self, name):
+        '''
+        Removes a widget (and its label if present) from the layout.
+        Decreases the counter for the number of widgets in the layout.
+        Deletes the field (and label) from the dictionary.
+        '''
+        self.widget().removeWidget(name)
+
+    def getNumWidgets(self):
+        '''
+        Returns the number of widgets in the form.
+        '''
+        return self.widget().getNumWidgets()
+
     def getWidget(self, name, role='field'):
         '''returns the Widget by the name with which it has been added
 

examples/remove_widgets_example.py

@@ -0,0 +1,130 @@
+import sys
+
+from PySide2 import QtWidgets
+
+from eqt.ui import FormDialog, UIFormWidget
+
+
+class MainUI(QtWidgets.QMainWindow):
+    def __init__(self, parent=None):
+        QtWidgets.QMainWindow.__init__(self, parent)
+
+        # create a FormDockWidget
+        dock = UIFormWidget.FormDockWidget(parent=self)
+        dock.setWindowTitle('Example remove widget')
+        self.addWidgetsToExampleForm(dock)
+
+        # add a button to dock to remove user selected widget
+        buttonuser = QtWidgets.QPushButton(dock)
+        buttonuser.setText("Remove user selected widget")
+        dock.addSpanningWidget(buttonuser, 'Button Remove User')
+        buttonuser.clicked.connect(lambda: self.remove(dock, buttonuser))
+
+        # create button for Form Dialog
+        pb = QtWidgets.QPushButton(self)
+        pb.setText("Open Form Dialog")
+        pb.clicked.connect(lambda: self.openFormDialog())
+
+        # create window layout
+        layout = QtWidgets.QHBoxLayout()
+        layout.addWidget(pb)
+        layout.addWidget(dock)
+        widg = QtWidgets.QWidget()
+        widg.setLayout(layout)
+        self.setCentralWidget(widg)
+
+        # print dictionary of all widgets in dock
+        print("\nDictionary of widgets in the Form Dock Widget:\n" + str(dock.getWidgets()))
+
+        self.show()
+
+    def openFormDialog(self):
+        dialog = FormDialog(parent=self, title='Example remove widget')
+        dialog.Ok.clicked.connect(lambda: self.remove(dialog, dialog.Ok))
+        self.addWidgetsToExampleForm(dialog)
+        dialog.addSpanningWidget(
+            QtWidgets.QLabel(
+                "Press `Ok` to remove the user selected widget and `Cancel` to close the dialog:"),
+            'ok_cancel_instructions')
+
+        # store a reference
+        self.dialog = dialog
+        self.dialog.onCancel = self.rejected
+
+        # print dictionary of all widgets in dialog
+        print("Dictionary of widgets in Form Dialog:\n" + str(self.dialog.getWidgets()))
+
+        dialog.open()
+
+    def addWidgetsToExampleForm(self, form):
+
+        # add widget 1 as QLineEdit
+        qlabel = QtWidgets.QLabel(form)
+        qlabel.setText("Widget 1: ")
+        qwidget = QtWidgets.QLineEdit(form)
+        qwidget.setClearButtonEnabled(True)
+        form.addWidget(qwidget, qlabel, 'Widget 1')
+
+        # add widget 2 as QLineEdit
+        qlabel = QtWidgets.QLabel(form)
+        qlabel.setText("Widget 2: ")
+        qwidget = QtWidgets.QLineEdit(form)
+        qwidget.setClearButtonEnabled(True)
+        form.addWidget(qwidget, qlabel, 'Widget 2')
+
+        # add widget 3 as QLineEdit
+        qlabel = QtWidgets.QLabel(form)
+        qlabel.setText("Widget 3: ")
+        qwidget = QtWidgets.QLineEdit(form)
+        qwidget.setClearButtonEnabled(True)
+        form.addWidget(qwidget, qlabel, 'Widget 3')
+
+        # add input as QComboBox
+        form.addSpanningWidget(QtWidgets.QLabel("Pick the widget you want to remove:"),
+                               'input_title')
+        qlabel = QtWidgets.QLabel(form)
+        qlabel.setText("User input: ")
+        qwidget = QtWidgets.QComboBox(form)
+        qwidget.addItem("Widget 2")
+        qwidget.addItem("Widget 3")
+        qwidget.setCurrentIndex(0)
+        qwidget.setEnabled(True)
+        form.addWidget(qwidget, qlabel, 'userinput')
+
+        # add a button to remove widget 1
+        button1 = QtWidgets.QPushButton(form)
+        button1.setText("Remove widget 1")
+        form.addSpanningWidget(button1, 'Button Remove w1')
+        button1.clicked.connect(lambda: self.remove(form, button1, 'Widget 1'))
+
+        # add a button to remove spanning widget
+        buttonspanning = QtWidgets.QPushButton(form)
+        buttonspanning.setText("Remove spanning widget")
+        form.addSpanningWidget(buttonspanning, 'Button Remove Spanning')
+        buttonspanning.clicked.connect(lambda: self.remove(form, buttonspanning, 'input_title'))
+
+    def rejected(self):
+        print("\nDialog closed.")
+
+    def remove(self, form, button, userselection=False):
+        if userselection is False:
+            userselection = form.getWidget('userinput').currentText()
+            form.getWidget('userinput').removeItem(form.getWidget('userinput').currentIndex())
+        print("\nRemove " + userselection)
+        form.removeWidget(userselection)
+        if form.getWidget('userinput').currentIndex() == -1:
+            button.setEnabled(False)
+        if button == form.getWidget('Button Remove w1') or button == form.getWidget(
+                'Button Remove Spanning'):
+            button.setEnabled(False)
+
+        print("\nDictionary of widgets after deletion of " + userselection + ":\n" +
+              str(form.getWidgets()))
+
+
+if __name__ == "__main__":
+    app = QtWidgets.QApplication(sys.argv)
+
+    window = MainUI()
+
+    sys.exit(app.exec_())

test/test__formUI_status_test.py

@@ -39,6 +39,37 @@ def add_two_widgets(self):
         form.addWidget(QtWidgets.QLabel('test label'), 'Label: ', 'label')
         form.addWidget(QtWidgets.QCheckBox('test checkbox'), 'CheckBox: ', 'checkBox')
 
+    def _test_remove_one_widget(self, name):
+        """
+            Remove one widget.
+            Checks the number of widgets in the form before and after deletion are consistent.
+            Checks the number of rows in the layout and number of widgets in the form are
+              consistent.
+
+            name: name in the dictionary of the widget to be removed
+            """
+        qwidget = self.form.getWidget(name, role='field')
+        rowpre, role = self.layout.getWidgetPosition(qwidget) # checks the widget exists
+        prerowcount = self.layout.rowCount()
+        predictionary = self.form.getWidgets().copy()
+        prenumwidgets = self.form.getNumWidgets()
+        self.form.removeWidget(name)
+        postrowcount = self.layout.rowCount()
+        postdictionary = self.form.getWidgets()
+        postnumwidgets = self.form.getNumWidgets()
+        self.assertNotEqual(predictionary, postdictionary)
+        self.assertEqual(prenumwidgets, postnumwidgets + 1)
+        self.assertEqual(prerowcount, postrowcount + 1)
+        self.assertEqual(postrowcount, postnumwidgets)
+
+    def test_remove_every_widget(self):
+        """Remove every widget from `self.form`"""
+        list_widgets = [
+            'label', 'checkBox', 'comboBox', 'doubleSpinBox', 'spinBox', 'slider',
+            'uiSliderWidget', 'radioButton', 'textEdit', 'plainTextEdit', 'lineEdit', 'button']
+        for name in list_widgets:
+            self._test_remove_one_widget(name)
+
     def test_getWidgetState_returns_visibility(self):
         """
         Check that the visibility of the widget is saved to the state
@@ -295,6 +326,7 @@ def setUp(self):
         self.add_every_widget()
         self.simple_form = FormDialog()
         self.add_two_widgets()
+        self.layout = self.form.formWidget.uiElements['groupBoxFormLayout']
 
     def test_getWidgetState_returns_QLabel_value(self):
         """Check that the value of the QLabel is saved to the state"""
@@ -369,6 +401,7 @@ def setUp(self):
         self.add_every_widget()
         self.simple_form = FormWidget()
         self.add_two_widgets()
+        self.layout = self.form.uiElements['groupBoxFormLayout']
 
     def test_getWidgetState_returns_QLabel_value(self):
         """Check that the value of the QLabel is saved to the state"""
@@ -443,6 +476,7 @@ def setUp(self):
         self.add_every_widget()
         self.simple_form = FormDockWidget()
         self.add_two_widgets()
+        self.layout = self.form.widget().uiElements['groupBoxFormLayout']
 
     def test_getWidgetState_returns_QLabel_value(self):
         """Check that the value of the QLabel is saved to the state"""