[processing] Add useCheckBoxes option to SelectionWidgetWrapper

This allow to show checkboxes or radioboxes intead of line edit with button.
This is configurable for each algorithm thought ParameterSelection metadata parameter.
It is also possible to choose the number of columns.
This is not applied in case of the BatchDialog.

python/plugins/processing/core/parameters.py

@@ -371,8 +371,8 @@ def __init__(self, name='', description='', optional=False, showSublayersDialog=
 class ParameterSelection(Parameter):
 
     def __init__(self, name='', description='', options=[], default=None, isSource=False,
-                 multiple=False, optional=False):
-        Parameter.__init__(self, name, description, default, optional)
+                 multiple=False, optional=False, metadata={}):
+        Parameter.__init__(self, name, description, default, optional, metadata)
         self.multiple = multiple
         isSource = parseBool(isSource)
         self.options = options

python/plugins/processing/gui/CheckboxesPanel.py

@@ -0,0 +1,89 @@
+# -*- coding: utf-8 -*-
+
+"""
+***************************************************************************
+    CheckBoxesPanel.py
+    ---------------------
+    Date                 : January 2015
+    Copyright            : (C) 2015 by Arnaud Morvan
+    Email                : arnaud dot morvan at camptocamp dot com
+    Contributors         : Arnaud Morvan
+***************************************************************************
+*                                                                         *
+*   This program is free software; you can redistribute it and/or modify  *
+*   it under the terms of the GNU General Public License as published by  *
+*   the Free Software Foundation; either version 2 of the License, or     *
+*   (at your option) any later version.                                   *
+*                                                                         *
+***************************************************************************
+"""
+from builtins import range
+
+__author__ = 'Arnaud Morvan'
+__date__ = 'January 2015'
+__copyright__ = '(C) 2015, Arnaud Morvan'
+
+# This will get replaced with a git SHA1 when you do a git archive
+__revision__ = '$Format:%H$'
+
+
+from qgis.PyQt.QtWidgets import (
+    QCheckBox,
+    QRadioButton,
+    QGridLayout,
+    QButtonGroup,
+    QSizePolicy,
+    QSpacerItem,
+    QWidget,
+)
+
+
+class CheckboxesPanel(QWidget):
+
+    def __init__(self, options, multiple, columns=2, parent=None):
+        super(CheckboxesPanel, self).__init__(parent)
+
+        self._options = []
+        for i, option in enumerate(options):
+            if isinstance(option, str):
+                self._options.append((i, option))
+            else:
+                self.options.append(option)
+        self._multiple = multiple
+        self._buttons = []
+        rows = len(options) / columns
+
+        self._buttonGroup = QButtonGroup()
+        self._buttonGroup.setExclusive(not multiple)
+        layout = QGridLayout()
+        for i, (v, t) in enumerate(self._options):
+            if multiple:
+                button = QCheckBox(t)
+            else:
+                button = QRadioButton(t)
+            self._buttons.append((v, button))
+            self._buttonGroup.addButton(button, i)
+            layout.addWidget(button, i % rows, i / rows)
+        layout.addItem(QSpacerItem(0, 0, QSizePolicy.Expanding, QSizePolicy.Minimum),
+                       0, columns)
+        self.setLayout(layout)
+
+    def value(self):
+        if self._multiple:
+            value = []
+            for (v, checkbox) in self._buttons:
+                if checkbox.isChecked():
+                    value.append(v)
+            return value
+        else:
+            return self._options[self._buttonGroup.checkedId()][0]
+
+    def setValue(self, value):
+        if self._multiple:
+            for (v, button) in self._buttons:
+                if v in value:
+                    button.setChecked(True)
+        else:
+            for v, button in self._buttons:
+                if v == value:
+                    button.setChecked(True)

python/plugins/processing/gui/wrappers.py

@@ -118,6 +118,7 @@
 from processing.core.outputs import (OutputFile, OutputRaster, OutputVector,
                                      OutputString, OutputTable, OutputExtent)
 from processing.tools import dataobjects
+from processing.gui.CheckboxesPanel import CheckboxesPanel
 from processing.gui.MultipleInputPanel import MultipleInputPanel
 from processing.gui.BatchInputSelectionPanel import BatchInputSelectionPanel
 from processing.gui.FixedTablePanel import FixedTablePanel
@@ -803,7 +804,12 @@ def selectFile(self):
 
 class EnumWidgetWrapper(WidgetWrapper):
 
-    def createWidget(self):
+    def createWidget(self, useCheckBoxes=False, columns=1):
+        self._useCheckBoxes = useCheckBoxes
+        if self._useCheckBoxes and not self.dialogType == DIALOG_BATCH:
+            return CheckboxesPanel(options=self.param.options(),
+                                   multiple=self.param.allowMultiple(),
+                                   columns=columns)
         if self.param.allowMultiple():
             return MultipleInputPanel(options=self.param.options())
         else:
@@ -815,12 +821,17 @@ def createWidget(self):
             return widget
 
     def setValue(self, value):
+        if self._useCheckBoxes and not self.dialogType == DIALOG_BATCH:
+            self.widget.setValue(value)
+            return
         if self.param.allowMultiple():
             self.widget.setSelectedItems(value)
         else:
             self.widget.setCurrentIndex(self.widget.findData(value))
 
     def value(self):
+        if self._useCheckBoxes and not self.dialogType == DIALOG_BATCH:
+            return self.widget.value()
         if self.param.allowMultiple():
             return self.widget.selectedoptions
         else: