From fe3b6ca5fe33d1e99d23e44c6982f040c95a7c82 Mon Sep 17 00:00:00 2001
From: Peter Hartmann <peter@edelhirsch.io>
Date: Fri, 14 Jul 2023 15:11:05 +0200
Subject: [PATCH] list view: Support focusing individual cells

---
 src/controls/QskListView.cpp        | 34 +++++++++++++++++++++++++++--
 src/controls/QskListView.h          |  2 ++
 src/controls/QskListViewSkinlet.cpp | 30 ++++++++++++++++++++-----
 src/controls/QskListViewSkinlet.h   |  3 +++
 4 files changed, 61 insertions(+), 8 deletions(-)

diff --git a/src/controls/QskListView.cpp b/src/controls/QskListView.cpp
index 952805c6..4c283d14 100644
--- a/src/controls/QskListView.cpp
+++ b/src/controls/QskListView.cpp
@@ -7,6 +7,7 @@
 #include "QskAspect.h"
 #include "QskColorFilter.h"
 #include "QskEvent.h"
+#include "QskSkinlet.h"
 
 #include <qguiapplication.h>
 #include <qstylehints.h>
@@ -40,6 +41,8 @@ QskListView::QskListView( QQuickItem* parent )
     , m_data( new PrivateData() )
 {
     setSubcontrolProxy( Inherited::Viewport, Viewport );
+
+    connect( this, &QskScrollView::scrollPosChanged, this, &QskControl::focusIndicatorRectChanged );
 }
 
 QskListView::~QskListView()
@@ -125,6 +128,7 @@ void QskListView::setSelectedRow( int row )
     {
         m_data->selectedRow = row;
         Q_EMIT selectedRowChanged( row );
+        Q_EMIT focusIndicatorRectChanged();
 
         update();
     }
@@ -161,6 +165,21 @@ QskColorFilter QskListView::graphicFilterAt( int row, int col ) const
     return QskColorFilter();
 }
 
+QRectF QskListView::focusIndicatorRect() const
+{
+    if( selectedRow() >= 0 )
+    {
+        auto rect = effectiveSkinlet()->sampleRect( this,
+            contentsRect(), Cell, selectedRow() );
+
+        const auto p = scrollPos();
+        rect.adjust( -p.x(), -p.y(), -p.x(), -p.y() );
+        return rect;
+    }
+
+    return Inherited::focusIndicatorRect();
+}
+
 void QskListView::keyPressEvent( QKeyEvent* event )
 {
     if ( m_data->selectionMode == NoSelection )
@@ -208,8 +227,19 @@ void QskListView::keyPressEvent( QKeyEvent* event )
         }
         default:
         {
-            Inherited::keyPressEvent( event );
-            return;
+            if ( const int steps = qskFocusChainIncrement( event ) )
+            {
+                row += steps;
+
+                if( row < 0 )
+                {
+                    row += rowCount();
+                }
+                else if( row >= rowCount() )
+                {
+                    row %= rowCount();
+                }
+            }
         }
     }
 
diff --git a/src/controls/QskListView.h b/src/controls/QskListView.h
index b6a9eb15..d66e4758 100644
--- a/src/controls/QskListView.h
+++ b/src/controls/QskListView.h
@@ -75,6 +75,8 @@ class QSK_EXPORT QskListView : public QskScrollView
     virtual QskColorFilter graphicFilterAt( int row, int col ) const;
 #endif
 
+    QRectF focusIndicatorRect() const override;
+
   public Q_SLOTS:
     void setSelectedRow( int row );
 
diff --git a/src/controls/QskListViewSkinlet.cpp b/src/controls/QskListViewSkinlet.cpp
index 0a26ccf4..6b44f6e1 100644
--- a/src/controls/QskListViewSkinlet.cpp
+++ b/src/controls/QskListViewSkinlet.cpp
@@ -127,8 +127,6 @@ void QskListViewSkinlet::updateBackgroundNodes(
         rowMax = listView->rowCount() - 1;
 
     const int rowSelected = listView->selectedRow();
-    const double x0 = viewRect.left() + scrolledPos.x();
-    const double y0 = viewRect.top();
 
     auto rowNode = backgroundNode->firstChild();
 
@@ -138,8 +136,7 @@ void QskListViewSkinlet::updateBackgroundNodes(
         {
             if ( row % 2 )
             {
-                const QRectF rect( x0, y0 + row * cellHeight,
-                    viewRect.width(), cellHeight );
+                const auto rect = sampleRect( listView, listView->contentsRect(), Q::Cell, row );
 
                 auto newNode = updateBoxNode( listView, rowNode, rect, Q::Cell );
                 if ( newNode )
@@ -158,8 +155,7 @@ void QskListViewSkinlet::updateBackgroundNodes(
         QskSkinStateChanger stateChanger( listView );
         stateChanger.setStates( listView->skinStates() | QskListView::Selected );
 
-        const QRectF rect( x0, y0 + rowSelected * cellHeight,
-            viewRect.width(), cellHeight );
+        const auto rect = sampleRect( listView, listView->contentsRect(), Q::Cell, rowSelected );
         
         rowNode = updateBoxNode( listView, rowNode, rect, Q::Cell );
         if ( rowNode && rowNode->parent() != backgroundNode )
@@ -490,4 +486,26 @@ QSizeF QskListViewSkinlet::sizeHint( const QskSkinnable* skinnable,
     return QSizeF( w, -1.0 );
 }
 
+QRectF QskListViewSkinlet::sampleRect( const QskSkinnable* skinnable,
+    const QRectF& contentsRect, QskAspect::Subcontrol subControl, int index ) const
+{
+    using Q = QskListView;
+    const auto listView = static_cast< const QskListView* >( skinnable );
+
+    if ( subControl == Q::Cell )
+    {
+        const auto cellHeight = listView->rowHeight();
+        const auto viewRect = listView->viewContentsRect();
+        const auto scrolledPos = listView->scrollPos();
+
+        const double x0 = viewRect.left() + scrolledPos.x();
+        const double y0 = viewRect.top();
+
+        const QRectF rect( x0, y0 + index * cellHeight, viewRect.width(), cellHeight );
+        return rect;
+    }
+
+    return Inherited::sampleRect( skinnable, contentsRect, subControl, index );
+}
+
 #include "moc_QskListViewSkinlet.cpp"
diff --git a/src/controls/QskListViewSkinlet.h b/src/controls/QskListViewSkinlet.h
index 7f2f9d88..4f174962 100644
--- a/src/controls/QskListViewSkinlet.h
+++ b/src/controls/QskListViewSkinlet.h
@@ -37,6 +37,9 @@ class QSK_EXPORT QskListViewSkinlet : public QskScrollViewSkinlet
     QSizeF sizeHint( const QskSkinnable*,
         Qt::SizeHint, const QSizeF& ) const override;
 
+    QRectF sampleRect( const QskSkinnable*,
+        const QRectF&, QskAspect::Subcontrol, int index ) const override;
+
   protected:
     QSGNode* updateContentsNode(
         const QskScrollView*, QSGNode* ) const override;