Add list section headings to tasks view

src/contents/ui/TodoTreeView.qml

@@ -37,6 +37,47 @@ TreeListView {
     currentIndex: -1
     clip: true
 
+    section.criteria: sortBy === Kalendar.TodoSortFilterProxyModel.SummaryColumn ?
+        ViewSection.FirstCharacter : ViewSection.FullString
+    section.property: switch(sortBy) {
+        case Kalendar.TodoSortFilterProxyModel.PriorityColumn:
+            return "topMostParentPriority";
+        case Kalendar.TodoSortFilterProxyModel.DueDateColumn:
+            return "topMostParentDueDate";
+        case Kalendar.TodoSortFilterProxyModel.SummaryColumn:
+        default:
+            return "topMostParentSummary";
+    }
+    section.delegate: Kirigami.AbstractListItem {
+        separatorVisible: false
+        sectionDelegate: true
+        hoverEnabled: false
+
+        activeFocusOnTab: false
+
+        contentItem: Kirigami.Heading {
+            text: {
+                switch(sortBy) {
+                    case Kalendar.TodoSortFilterProxyModel.PriorityColumn:
+                        return section !== "--" ? i18n("Priority %1", section) : i18n("No set priority");
+                    case Kalendar.TodoSortFilterProxyModel.DueDateColumn:
+                        let sectionDate = new Date(section);
+                        return !isNaN(sectionDate.getTime()) ? LabelUtils.todoDateTimeLabel(new Date(section), true, false) : section;
+                    case Kalendar.TodoSortFilterProxyModel.SummaryColumn:
+                    default:
+                        return section;
+                }
+
+            }
+            readonly property bool isOverdue: section === i18n("Overdue")
+            readonly property bool isToday: DateUtils.sameDay(new Date(section), new Date())
+
+            level: 3
+            font.weight: Font.Bold
+            color: isOverdue ? Kirigami.Theme.negativeTextColor : isToday ? Kirigami.Theme.highlightColor : Kirigami.Theme.textColor
+        }
+    }
+
     MouseArea {
         id: incidenceDeselectorMouseArea
         anchors.fill: parent

src/contents/ui/labelutils.js

@@ -211,9 +211,9 @@ function todoDateTimeLabel(datetime, allDay, completed) {
             i18nc("%1 is the time, spaces included to allow use of 'empty' string when an event is allday and has no time", " at %1 ", datetime.toLocaleTimeString(Qt.locale(), 1));
 
         if(DateUtils.sameDay(datetime, now)) {
-            return (datetime > now || allDay) && !completed ?
-                i18nc("No space since the %1 string, which includes the time (or not), includes this space", "Today%1", timeString) :
-                i18nc("No space since the %1 string, which includes the time (or not), includes this space", "Today%1(overdue)", timeString);
+            return (datetime > now) && !completed && !allDay ?
+                i18nc("No space since the %1 string, which includes the time (or not), includes this space", "Today%1(overdue)", timeString) :
+                i18nc("No space since the %1 string, which includes the time (or not), includes this space", "Today%1", timeString);
         } else if(DateUtils.sameDay(DateUtils.addDaysToDate(datetime, - 1), now)) { // Tomorrow
             return i18nc("No space since the %1 string, which includes the time (or not), includes this space", "Tomorrow%1", timeString);
         } else if(DateUtils.sameDay(DateUtils.addDaysToDate(datetime, 1), now)) { // Yesterday

src/extratodomodel.cpp

 // SPDX-FileCopyrightText: 2021 Claudio Cambra <claudio.cambra@gmail.com>
 // SPDX-License-Identifier: LGPL-2.1-or-later
 
+#include <QDateTime>
 #include <extratodomodel.h>
 
 ExtraTodoModel::ExtraTodoModel(QObject *parent)
@@ -111,14 +112,29 @@ QVariant ExtraTodoModel::data(const QModelIndex &index, int role) const
         return todoPtr->categories();
     } else if (role == Roles::CategoriesDisplayRole) {
         return todoPtr->categories().join(i18nc("List separator", ", "));
-    } else if (role == Roles::TreeDepthRole) {
+    } else if (role == Roles::TreeDepthRole || role == TopMostParentSummary || role == TopMostParentDueDate || role == TopMostParentPriority) {
         int depth = 0;
         auto idx = index;
         while (idx.parent().isValid()) {
             idx = idx.parent();
             depth++;
         }
-        return depth;
+
+        auto todo = idx.data(TodoModel::TodoPtrRole).value<KCalendarCore::Todo::Ptr>();
+
+        switch (role) {
+        case Roles::TreeDepthRole:
+            return depth;
+        case TopMostParentSummary:
+            return todo->summary();
+        case TopMostParentDueDate: {
+            bool isOverdue = (todo->hasDueDate() && todo->dtDue().date() < QDate::currentDate() && todo->allDay())
+                || (todo->hasDueDate() && todo->dtDue() < QDateTime::currentDateTime() && !todo->allDay());
+            return isOverdue ? i18n("Overdue") : todo->hasDueDate() ? todo->dtDue().toString() : i18n("No set date");
+        }
+        case TopMostParentPriority:
+            return todo->priority();
+        }
     }
 
     return KExtraColumnsProxyModel::data(index, role);
@@ -149,6 +165,9 @@ QHash<int, QByteArray> ExtraTodoModel::roleNames() const
     roleNames[Roles::CategoriesRole] = "todoCategories"; // Simply 'categories' causes issues
     roleNames[Roles::CategoriesDisplayRole] = "categoriesDisplay";
     roleNames[Roles::TreeDepthRole] = "treeDepth";
+    roleNames[Roles::TopMostParentDueDate] = "topMostParentDueDate";
+    roleNames[Roles::TopMostParentSummary] = "topMostParentSummary";
+    roleNames[Roles::TopMostParentPriority] = "topMostParentPriority";
 
     return roleNames;
 }

src/extratodomodel.h

@@ -43,7 +43,10 @@ public:
         ItemRole,
         CategoriesRole,
         CategoriesDisplayRole,
-        TreeDepthRole
+        TreeDepthRole,
+        TopMostParentSummary, // These three here are used to help us conserve the proper sections
+        TopMostParentDueDate, // in the Kirigami TreeListView, which otherwise will create new
+        TopMostParentPriority // sections for subtasks
     };
     Q_ENUM(Roles);