Bug 1854424 - Add a LogicalMargin method returning an offset to start-sides. r=layout-reviewers,jfkthame

Differential Revision: https://phabricator.services.mozilla.com/D188847

layout/forms/nsDateTimeControlFrame.cpp

@@ -135,9 +135,8 @@ void nsDateTimeControlFrame::Reflow(nsPresContext* aPresContext,
     LogicalMargin childMargin = childReflowInput.ComputedLogicalMargin(myWM);
 
     // offsets of input area frame within this frame:
-    LogicalPoint childOffset(
-        myWM, borderPadding.IStart(myWM) + childMargin.IStart(myWM),
-        borderPadding.BStart(myWM) + childMargin.BStart(myWM));
+    LogicalPoint childOffset =
+        borderPadding.StartOffset(myWM) + childMargin.StartOffset(myWM);
 
     nsReflowStatus childStatus;
     // We initially reflow the child with a dummy containerSize; positioning

layout/generic/WritingModes.h

@@ -1341,6 +1341,15 @@ class LogicalMargin {
     return LogicalSize(aWritingMode, IStartEnd(), BStartEnd());
   }
 
+  /**
+   * Return a LogicalPoint representing an offset to the start-sides, i.e.
+   * inline-start and block-start.
+   */
+  LogicalPoint StartOffset(WritingMode aWritingMode) const {
+    CHECK_WRITING_MODE(aWritingMode);
+    return LogicalPoint(aWritingMode, IStart(), BStart());
+  }
+
   /**
    * Accessors for physical margins, using our writing mode to convert from
    * logical values.

layout/generic/nsAbsoluteContainingBlock.cpp

@@ -840,11 +840,10 @@ void nsAbsoluteContainingBlock::ReflowAbsoluteFrame(
     }
 
     LogicalRect rect(outerWM,
-                     border.IStart(outerWM) + offsets.IStart(outerWM) +
-                         margin.IStart(outerWM),
-                     border.BStart(outerWM) + offsets.BStart(outerWM) +
-                         margin.BStart(outerWM),
-                     kidSize.ISize(outerWM), kidSize.BSize(outerWM));
+                     border.StartOffset(outerWM) +
+                         offsets.StartOffset(outerWM) +
+                         margin.StartOffset(outerWM),
+                     kidSize);
     nsRect r = rect.GetPhysicalRect(
         outerWM, logicalCBSize.GetPhysicalSize(wm) +
                      border.Size(outerWM).GetPhysicalSize(outerWM));

layout/generic/nsFlexContainerFrame.cpp

@@ -5400,8 +5400,8 @@ std::tuple<nscoord, bool> nsFlexContainerFrame::ReflowChildren(
   // flex container's content box (with respect to its border-box), so that
   // we can compute our flex item's final positions.
   WritingMode flexWM = aReflowInput.GetWritingMode();
-  const LogicalPoint containerContentBoxOrigin(
-      flexWM, aBorderPadding.IStart(flexWM), aBorderPadding.BStart(flexWM));
+  const LogicalPoint containerContentBoxOrigin =
+      aBorderPadding.StartOffset(flexWM);
 
   // The block-end of children is relative to the flex container's border-box.
   nscoord maxBlockEndEdgeOfChildren = containerContentBoxOrigin.B(flexWM);