From a59d9f85fa770a00d10e66025e102c736e18fa70 Mon Sep 17 00:00:00 2001
From: Amol Godbole <amolagodbole@gmail.com>
Date: Fri, 13 Oct 2023 21:08:35 -0500
Subject: KItemListView: add view position in scrollToItem()

An item, on being scrolled to, is always located at the nearest edge of
the view. This is not always convenient. Allow specifying where the item
should be positioned with respect to the view in scrollToItem().

BUG: 423884
---
 src/kitemviews/kitemlistview.cpp | 60 ++++++++++++++++++++++++++++++++--------
 1 file changed, 48 insertions(+), 12 deletions(-)

(limited to 'src/kitemviews/kitemlistview.cpp')

diff --git a/src/kitemviews/kitemlistview.cpp b/src/kitemviews/kitemlistview.cpp
index 457c02ec5..be22b91cc 100644
--- a/src/kitemviews/kitemlistview.cpp
+++ b/src/kitemviews/kitemlistview.cpp
@@ -537,7 +537,7 @@ bool KItemListView::isElided(int index) const
     return m_sizeHintResolver->isElided(index);
 }
 
-void KItemListView::scrollToItem(int index)
+void KItemListView::scrollToItem(int index, ViewItemPosition viewItemPosition)
 {
     QRectF viewGeometry = geometry();
     if (m_headerWidget->isVisible()) {
@@ -546,29 +546,65 @@ void KItemListView::scrollToItem(int index)
     }
     QRectF currentRect = itemRect(index);
 
-    // Fix for Bug 311099 - View the underscore when using Ctrl + PagDown
+    // Fix for Bug 311099 - View the underscore when using Ctrl + PageDown
     currentRect.adjust(-m_styleOption.horizontalMargin, -m_styleOption.verticalMargin, m_styleOption.horizontalMargin, m_styleOption.verticalMargin);
 
-    if (!viewGeometry.contains(currentRect)) {
-        qreal newOffset = scrollOffset();
-        if (scrollOrientation() == Qt::Vertical) {
+    qreal newOffset = scrollOffset();
+    if (scrollOrientation() == Qt::Vertical && (currentRect.top() < viewGeometry.top() || currentRect.bottom() > viewGeometry.bottom())) {
+        switch (viewItemPosition) {
+        case Beginning:
+            newOffset += currentRect.top() - viewGeometry.top();
+            break;
+        case Middle:
+            newOffset += 0.5 * (currentRect.top() + currentRect.bottom() - (viewGeometry.top() + viewGeometry.bottom()));
+            break;
+        case End:
+            newOffset += currentRect.bottom() - viewGeometry.bottom();
+            break;
+        case Nearest:
             if (currentRect.top() < viewGeometry.top()) {
                 newOffset += currentRect.top() - viewGeometry.top();
-            } else if (currentRect.bottom() > viewGeometry.bottom()) {
+            } else {
                 newOffset += currentRect.bottom() - viewGeometry.bottom();
             }
-        } else {
+            break;
+        default:
+            Q_UNREACHABLE();
+        }
+    } else if (scrollOrientation() == Qt::Horizontal && (currentRect.left() < viewGeometry.left() || currentRect.right() > viewGeometry.right())) {
+        switch (viewItemPosition) {
+        case Beginning:
+            if (layoutDirection() == Qt::RightToLeft) {
+                newOffset += currentRect.right() - viewGeometry.right();
+            } else {
+                newOffset += currentRect.left() - viewGeometry.left();
+            }
+            break;
+        case Middle:
+            newOffset += 0.5 * (currentRect.left() + currentRect.right() - (viewGeometry.left() + viewGeometry.right()));
+            break;
+        case End:
+            if (layoutDirection() == Qt::RightToLeft) {
+                newOffset += currentRect.left() - viewGeometry.left();
+            } else {
+                newOffset += currentRect.right() - viewGeometry.right();
+            }
+            break;
+        case Nearest:
             if (currentRect.left() < viewGeometry.left()) {
                 newOffset += currentRect.left() - viewGeometry.left();
-            } else if (currentRect.right() > viewGeometry.right()) {
+            } else {
                 newOffset += currentRect.right() - viewGeometry.right();
             }
+            break;
+        default:
+            Q_UNREACHABLE();
         }
+    }
 
-        if (newOffset != scrollOffset()) {
-            Q_EMIT scrollTo(newOffset);
-            return;
-        }
+    if (newOffset != scrollOffset()) {
+        Q_EMIT scrollTo(newOffset);
+        return;
     }
 
     Q_EMIT scrollingStopped();
-- 
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