QQuickTableView: combine layouts and rebuilds into the same code path

Rather than handle relayouts differenty than rebuilds, we
can make it a part of the rebuild structure instead, since
they overlap a lot. That way we can collect everything
that needs to be updated into a single variable (rebuildOptions).
This will simplify the upcoming work for synchronizing tableviews.

Change-Id: I8bb2638612c86194a854e6fefc998eae22357a7a
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

2 files changed, 28 insertions, 32 deletions

diff --git a/src/quick/items/qquicktableview.cpp b/src/quick/items/qquicktableview.cpp
index 12faac8127..9bc6723cbd 100644
--- a/src/quick/items/qquicktableview.cpp
+++ b/src/quick/items/qquicktableview.cpp
@@ -709,9 +709,8 @@ void QQuickTableViewPrivate::syncLoadedTableRectFromLoadedTable()
 
 void QQuickTableViewPrivate::forceLayout()
 {
-    columnRowPositionsInvalid = true;
     clearEdgeSizeCache();
-    RebuildOptions rebuildOptions = RebuildOption::None;
+    RebuildOptions rebuildOptions = RebuildOption::LayoutOnly;
 
     // Go through all columns from first to last, find the columns that used
     // to be hidden and not loaded, and check if they should become visible
@@ -750,8 +749,7 @@ void QQuickTableViewPrivate::forceLayout()
         break;
     }
 
-    if (rebuildOptions)
-        scheduleRebuildTable(rebuildOptions);
+    scheduleRebuildTable(rebuildOptions);
 
     if (polishing) {
         qWarning() << "TableView::forceLayout(): Cannot do an immediate re-layout during an ongoing layout!";
@@ -1195,7 +1193,6 @@ void QQuickTableViewPrivate::relayoutTable()
 void QQuickTableViewPrivate::relayoutTableItems()
 {
     qCDebug(lcTableViewDelegateLifecycle);
-    columnRowPositionsInvalid = false;
 
     qreal nextColumnX = loadedTableOuterRect.x();
     qreal nextRowY = loadedTableOuterRect.y();
@@ -1465,7 +1462,13 @@ bool QQuickTableViewPrivate::moveToNextRebuildState()
         // that the current state is not yet done.
         return false;
     }
-    rebuildState = RebuildState(int(rebuildState) + 1);
+
+    if (rebuildState == RebuildState::Begin
+            && rebuildOptions.testFlag(RebuildOption::LayoutOnly))
+        rebuildState = RebuildState::LayoutTable;
+    else
+        rebuildState = RebuildState(int(rebuildState) + 1);
+
     qCDebug(lcTableViewDelegateLifecycle()) << int(rebuildState);
     return true;
 }
@@ -1527,7 +1530,6 @@ void QQuickTableViewPrivate::beginRebuildTable()
     loadedRows.clear();
     loadedTableOuterRect = QRect();
     loadedTableInnerRect = QRect();
-    columnRowPositionsInvalid = false;
     clearEdgeSizeCache();
 
     if (topLeft.x() == kEdgeIndexAtEnd || topLeft.y() == kEdgeIndexAtEnd) {
@@ -1541,12 +1543,14 @@ void QQuickTableViewPrivate::beginRebuildTable()
 
 void QQuickTableViewPrivate::layoutAfterLoadingInitialTable()
 {
-    if (rowHeightProvider.isUndefined() || columnWidthProvider.isUndefined()) {
+    if (rebuildOptions.testFlag(RebuildOption::LayoutOnly)
+            || rowHeightProvider.isUndefined() || columnWidthProvider.isUndefined()) {
         // Since we don't have both size providers, we need to calculate the
         // size of each row and column based on the size of the delegate items.
         // This couldn't be done while we were loading the initial rows and
         // columns, since during the process, we didn't have all the items
-        // available yet for the calculation. So we do it now.
+        // available yet for the calculation. So we do it now. The exception
+        // is if we specifically only requested a relayout.
         relayoutTable();
     }
 
@@ -1708,11 +1712,6 @@ void QQuickTableViewPrivate::scheduleRebuildTable(RebuildOptions options) {
     q_func()->polish();
 }
 
-void QQuickTableViewPrivate::invalidateColumnRowPositions() {
-    columnRowPositionsInvalid = true;
-    q_func()->polish();
-}
-
 void QQuickTableViewPrivate::updatePolish()
 {
     // Whenever something changes, e.g viewport moves, spacing is set to a
@@ -1745,13 +1744,6 @@ void QQuickTableViewPrivate::updatePolish()
     if (loadedItems.isEmpty())
         return;
 
-    if (columnRowPositionsInvalid) {
-        relayoutTable();
-        updateAverageEdgeSize();
-        updateContentWidth();
-        updateContentHeight();
-    }
-
     loadAndUnloadVisibleEdges();
 }
 
@@ -1856,10 +1848,15 @@ void QQuickTableViewPrivate::syncRebuildOptions()
     rebuildOptions = scheduledRebuildOptions;
     scheduledRebuildOptions = RebuildOption::None;
 
-    if (loadedItems.isEmpty()) {
-        // If we have no items from before, we cannot just rebuild the viewport, but need
-        // to rebuild everything, since we have no top-left loaded item to start from.
+    if (loadedItems.isEmpty())
         rebuildOptions.setFlag(RebuildOption::All);
+
+    // Some options are exclusive:
+    if (rebuildOptions.testFlag(RebuildOption::All)) {
+        rebuildOptions.setFlag(RebuildOption::ViewportOnly, false);
+        rebuildOptions.setFlag(RebuildOption::LayoutOnly, false);
+    } else if (rebuildOptions.testFlag(RebuildOption::ViewportOnly)) {
+        rebuildOptions.setFlag(RebuildOption::LayoutOnly, false);
     }
 }
 
@@ -2073,7 +2070,7 @@ void QQuickTableView::setRowSpacing(qreal spacing)
         return;
 
     d->cellSpacing.setHeight(spacing);
-    d->invalidateColumnRowPositions();
+    d->scheduleRebuildTable(QQuickTableViewPrivate::RebuildOption::LayoutOnly);
     emit rowSpacingChanged();
 }
 
@@ -2091,7 +2088,7 @@ void QQuickTableView::setColumnSpacing(qreal spacing)
         return;
 
     d->cellSpacing.setWidth(spacing);
-    d->invalidateColumnRowPositions();
+    d->scheduleRebuildTable(QQuickTableViewPrivate::RebuildOption::LayoutOnly);
     emit columnSpacingChanged();
 }
 
diff --git a/src/quick/items/qquicktableview_p_p.h b/src/quick/items/qquicktableview_p_p.h
index 53bd6ec973..acf537198b 100644
--- a/src/quick/items/qquicktableview_p_p.h
+++ b/src/quick/items/qquicktableview_p_p.h
@@ -188,10 +188,11 @@ public:
 
     enum class RebuildOption {
         None = 0,
-        ViewportOnly = 0x1,
-        CalculateNewTopLeftRow = 0x2,
-        CalculateNewTopLeftColumn = 0x4,
-        All = 0x8,
+        LayoutOnly = 0x1,
+        ViewportOnly = 0x2,
+        CalculateNewTopLeftRow = 0x4,
+        CalculateNewTopLeftColumn = 0x8,
+        All = 0x10,
     };
     Q_DECLARE_FLAGS(RebuildOptions, RebuildOption)
 
@@ -246,7 +247,6 @@ public:
     QQmlTableInstanceModel::ReusableFlag reusableFlag = QQmlTableInstanceModel::Reusable;
 
     bool blockItemCreatedCallback = false;
-    bool columnRowPositionsInvalid = false;
     bool layoutWarningIssued = false;
     bool polishing = false;
 
@@ -356,7 +356,6 @@ public:
     void layoutAfterLoadingInitialTable();
 
     void scheduleRebuildTable(QQuickTableViewPrivate::RebuildOptions options);
-    void invalidateColumnRowPositions();
 
     int resolveImportVersion();
     void createWrapperModel();