Fix a problem with using form layouts (#125)

* Fix a problem with using form layouts
* Bump version

Author: berendkleinhaneveld

collagraph/renderers/pyside/objects/layouts.py

@@ -59,8 +59,15 @@ def remove_layout(self, el):
 
 @PySideRenderer.register_remove(QFormLayout)
 def remove_form(self, el):
-    # Layout also deletes 'el' so no need to unset parent
-    self.removeRow(el)
+    # Don't use removeRow, even though it should theoratically work
+    # In reality it causes a hard crash...
+    # Instead, take the row, and then unset the parents of the
+    # associated widgets of the return layout item
+    layout_item = self.takeRow(el)
+    if layout_item:
+        layout_item.labelItem.widget().setParent(None)
+        layout_item.fieldItem.widget().setParent(None)
+    el.setParent(None)
 
 
 @PySideRenderer.register_set_attr(QLayout)
@@ -105,12 +112,31 @@ def set_grid_index(self, attr, value):
         layout.addWidget(self, *value)
 
 
-@PySideRenderer.register_custom_attribute("form_label", "form_index")
+@PySideRenderer.register_custom_attribute("form_label")
+def set_form_label(self, attr, value):
+    setattr(self, attr, value)
+    index = getattr(self, "form_index", None)
+    if parent := self.parent():
+        layout = parent.layout()
+        if index is not None:
+            label_item = layout.itemAt(index, QFormLayout.LabelRole)
+            label_item.widget().setText(value)
+
+
+@PySideRenderer.register_custom_attribute("form_index")
 def set_form_index(self, attr, value):
+    old_index = getattr(self, "form_index", None)
     setattr(self, attr, value)
     if parent := self.parent():
         layout = parent.layout()
+        label_widget = None
+        if old_index is not None:
+            layout_item = layout.takeRow(old_index)
+            label_widget = layout_item.labelItem.widget()
+            assert layout_item.fieldItem.widget() is self
         if hasattr(self, "form_label") and hasattr(self, "form_index"):
-            layout.insertRow(self.form_index, self.form_label, self)
+            layout.insertRow(
+                self.form_index, label_widget if label_widget else self.form_label, self
+            )
         elif hasattr(self, "form_label"):
             layout.addRow(self.form_label, self)

examples/pyside/list_and_form.cgx

@@ -0,0 +1,47 @@
+<widget>
+  <qsplitter>
+    <treewidget
+      object-name="tree-widget"
+      :header-labels="['content']"
+      :column-count="1"
+      :selection-mode="QtWidgets.QTreeView.ExtendedSelection"
+      @item-selection-changed="selection_changed"
+    >
+      <treewidgetitem
+        v-for="item in items"
+        :content="{0: item['name']}"
+        :obj_id="item['id']"
+      />
+    </treewidget>
+    <widget :layout="{'type': 'form'}">
+      <label v-for="item in selected_items()" v-bind="item" />
+    </widget>
+  </qsplitter>
+</widget>
+
+<script>
+import collagraph as cg
+from PySide6 import QtWidgets
+
+class App(cg.Component):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.state["items"] = [{"id": 0, "name": "first"}, {"id": 1, "name":"second"}]
+        self.state["selected"] = []
+
+    def selection_changed(self):
+        if not self.element:
+            return
+
+        tree_widget = self.element.findChild(QtWidgets.QTreeWidget, "tree-widget")
+        selected_items = tree_widget.selectedItems()
+        selected_ids = list([item.obj_id for item in selected_items])
+        self.state["selected"] = selected_ids
+
+    def selected_items(self):
+        result = [
+            {'text': self.state['items'][idx]["name"], 'form_label': f'Type {idx}:', 'form_index': 0}
+            for idx in self.state['selected']]
+        return result
+
+</script>

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "collagraph"
-version = "0.8.2"
+version = "0.8.3"
 description = "Reactive user interfaces"
 authors = [
     { name = "Berend Klein Haneveld", email = "berendkleinhaneveld@gmail.com" },