Add m-esr52 at 52.6.0

1 files changed, 1276 insertions, 0 deletions

diff --git a/layout/xul/grid/nsGrid.cpp b/layout/xul/grid/nsGrid.cpp
new file mode 100644
index 000000000..762bbfcd7
--- /dev/null
+++ b/layout/xul/grid/nsGrid.cpp
@@ -0,0 +1,1276 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//
+// Eric Vaughan
+// Netscape Communications
+//
+// See documentation in associated header file
+//
+
+#include "nsGrid.h"
+#include "nsGridRowGroupLayout.h"
+#include "nsBox.h"
+#include "nsIScrollableFrame.h"
+#include "nsSprocketLayout.h"
+#include "nsGridLayout2.h"
+#include "nsGridRow.h"
+#include "nsGridCell.h"
+#include "mozilla/ReflowInput.h"
+
+/*
+The grid control expands the idea of boxes from 1 dimension to 2 dimensions. 
+It works by allowing the XUL to define a collection of rows and columns and then 
+stacking them on top of each other. Here is and example.
+
+Example 1:
+
+<grid>
+   <columns>
+      <column/>
+      <column/>
+   </columns>
+
+   <rows>
+      <row/>
+      <row/>
+   </rows>
+</grid>
+
+example 2:
+
+<grid>
+   <columns>
+      <column flex="1"/>
+      <column flex="1"/>
+   </columns>
+
+   <rows>
+      <row>
+         <text value="hello"/>
+         <text value="there"/>
+      </row>
+   </rows>
+</grid>
+
+example 3:
+
+<grid>
+
+<rows>
+      <row>
+         <text value="hello"/>
+         <text value="there"/>
+      </row>
+   </rows>
+
+   <columns>
+      <column>
+         <text value="Hey I'm in the column and I'm on top!"/>
+      </column>
+      <column/>
+   </columns>
+
+</grid>
+
+Usually the columns are first and the rows are second, so the rows will be drawn on top of the columns. 
+You can reverse this by defining the rows first.
+Other tags are then placed in the <row> or <column> tags causing the grid to accommodate everyone.  
+It does this by creating 3 things: A cellmap, a row list, and a column list. The cellmap is a 2 
+dimensional array of nsGridCells. Each cell contains 2 boxes.  One cell from the column list 
+and one from the row list. When a cell is asked for its size it returns that smallest size it can 
+be to accommodate the 2 cells. Row lists and Column lists use the same data structure: nsGridRow. 
+Essentially a row and column are the same except a row goes alone the x axis and a column the y. 
+To make things easier and save code everything is written in terms of the x dimension. A flag is 
+passed in called "isHorizontal" that can flip the calculations to the y axis.
+
+Usually the number of cells in a row match the number of columns, but not always. 
+It is possible to define 5 columns for a grid but have 10 cells in one of the rows. 
+In this case 5 extra columns will be added to the column list to handle the situation. 
+These are called extraColumns/Rows.
+*/
+
+using namespace mozilla;
+
+nsGrid::nsGrid():mBox(nullptr),
+                 mRowsBox(nullptr),
+                 mColumnsBox(nullptr),
+                 mNeedsRebuild(true),
+                 mRowCount(0),
+                 mColumnCount(0),
+                 mExtraRowCount(0),
+                 mExtraColumnCount(0),
+                 mMarkingDirty(false)
+{
+    MOZ_COUNT_CTOR(nsGrid);
+}
+
+nsGrid::~nsGrid()
+{
+    FreeMap();
+    MOZ_COUNT_DTOR(nsGrid);
+}
+
+/*
+ * This is called whenever something major happens in the grid. And example 
+ * might be when many cells or row are added. It sets a flag signaling that 
+ * all the grids caches information should be recalculated.
+ */
+void
+nsGrid::NeedsRebuild(nsBoxLayoutState& aState)
+{
+  if (mNeedsRebuild)
+    return;
+
+  // iterate through columns and rows and dirty them
+  mNeedsRebuild = true;
+
+  // find the new row and column box. They could have 
+  // been changed.
+  mRowsBox = nullptr;
+  mColumnsBox = nullptr;
+  FindRowsAndColumns(&mRowsBox, &mColumnsBox);
+
+  // tell all the rows and columns they are dirty
+  DirtyRows(mRowsBox, aState);
+  DirtyRows(mColumnsBox, aState);
+}
+
+
+
+/**
+ * If we are marked for rebuild. Then build everything
+ */
+void
+nsGrid::RebuildIfNeeded()
+{
+  if (!mNeedsRebuild)
+    return;
+
+  mNeedsRebuild = false;
+
+  // find the row and columns frames
+  FindRowsAndColumns(&mRowsBox, &mColumnsBox);
+
+  // count the rows and columns
+  int32_t computedRowCount = 0;
+  int32_t computedColumnCount = 0;
+  int32_t rowCount = 0;
+  int32_t columnCount = 0;
+
+  CountRowsColumns(mRowsBox, rowCount, computedColumnCount);
+  CountRowsColumns(mColumnsBox, columnCount, computedRowCount);
+
+  // computedRowCount are the actual number of rows as determined by the 
+  // columns children.
+  // computedColumnCount are the number of columns as determined by the number
+  // of rows children.
+  // We can use this information to see how many extra columns or rows we need.
+  // This can happen if there are are more children in a row that number of columns
+  // defined. Example:
+  //
+  // <columns>
+  //   <column/>
+  // </columns>
+  //
+  // <rows>
+  //   <row>
+  //     <button/><button/>
+  //   </row>
+  // </rows>
+  //
+  // computedColumnCount = 2 // for the 2 buttons in the row tag
+  // computedRowCount = 0 // there is nothing in the  column tag
+  // mColumnCount = 1 // one column defined
+  // mRowCount = 1 // one row defined
+  // 
+  // So in this case we need to make 1 extra column.
+  //
+
+  // Make sure to update mExtraColumnCount no matter what, since it might
+  // happen that we now have as many columns as are defined, and we wouldn't
+  // want to have a positive mExtraColumnCount hanging about in that case!
+  mExtraColumnCount = computedColumnCount - columnCount;
+  if (computedColumnCount > columnCount) {
+     columnCount = computedColumnCount;
+  }
+
+  // Same for rows.
+  mExtraRowCount = computedRowCount - rowCount;
+  if (computedRowCount > rowCount) {
+     rowCount = computedRowCount;
+  }
+
+  // build and poplulate row and columns arrays
+  mRows = BuildRows(mRowsBox, rowCount, true);
+  mColumns = BuildRows(mColumnsBox, columnCount, false);
+
+  // build and populate the cell map
+  mCellMap = BuildCellMap(rowCount, columnCount);
+
+  mRowCount = rowCount;
+  mColumnCount = columnCount;
+
+  // populate the cell map from column and row children
+  PopulateCellMap(mRows.get(), mColumns.get(), mRowCount, mColumnCount, true);
+  PopulateCellMap(mColumns.get(), mRows.get(), mColumnCount, mRowCount, false);
+}
+
+void
+nsGrid::FreeMap()
+{
+  mRows = nullptr;
+  mColumns = nullptr;
+  mCellMap = nullptr;
+  mColumnCount = 0;
+  mRowCount = 0;
+  mExtraColumnCount = 0;
+  mExtraRowCount = 0;
+  mRowsBox = nullptr;
+  mColumnsBox = nullptr;
+}
+
+/**
+ * finds the first <rows> and <columns> tags in the <grid> tag
+ */
+void
+nsGrid::FindRowsAndColumns(nsIFrame** aRows, nsIFrame** aColumns)
+{
+  *aRows = nullptr;
+  *aColumns = nullptr;
+
+  // find the boxes that contain our rows and columns
+  nsIFrame* child = nullptr;
+  // if we have <grid></grid> then mBox will be null (bug 125689)
+  if (mBox)
+    child = nsBox::GetChildXULBox(mBox);
+
+  while(child)
+  {
+    nsIFrame* oldBox = child;
+    nsIScrollableFrame *scrollFrame = do_QueryFrame(child);
+    if (scrollFrame) {
+       nsIFrame* scrolledFrame = scrollFrame->GetScrolledFrame();
+       NS_ASSERTION(scrolledFrame,"Error no scroll frame!!");
+       child = do_QueryFrame(scrolledFrame);
+    }
+
+    nsCOMPtr<nsIGridPart> monument = GetPartFromBox(child);
+    if (monument)
+    {
+      nsGridRowGroupLayout* rowGroup = monument->CastToRowGroupLayout();
+      if (rowGroup) {
+         bool isHorizontal = !nsSprocketLayout::IsXULHorizontal(child);
+         if (isHorizontal)
+           *aRows = child;
+         else
+           *aColumns = child;
+
+         if (*aRows && *aColumns)
+           return;
+      }
+    }
+
+    if (scrollFrame) {
+      child = oldBox;
+    }
+
+    child = nsBox::GetNextXULBox(child);
+  }
+}
+
+/**
+ * Count the number of rows and columns in the given box. aRowCount well become the actual number
+ * rows defined in the xul. aComputedColumnCount will become the number of columns by counting the number
+ * of cells in each row.
+ */
+void
+nsGrid::CountRowsColumns(nsIFrame* aRowBox, int32_t& aRowCount, int32_t& aComputedColumnCount)
+{
+  aRowCount = 0;
+  aComputedColumnCount = 0;
+  // get the rowboxes layout manager. Then ask it to do the work for us
+  if (aRowBox) {
+    nsCOMPtr<nsIGridPart> monument = GetPartFromBox(aRowBox);
+    if (monument) 
+       monument->CountRowsColumns(aRowBox, aRowCount, aComputedColumnCount);
+  }
+}
+
+
+/**
+ * Given the number of rows create nsGridRow objects for them and full them out.
+ */
+UniquePtr<nsGridRow[]>
+nsGrid::BuildRows(nsIFrame* aBox, int32_t aRowCount, bool aIsHorizontal)
+{
+  // if no rows then return null
+  if (aRowCount == 0) {
+    return nullptr;
+  }
+
+  // create the array
+  UniquePtr<nsGridRow[]> row;
+  
+  // only create new rows if we have to. Reuse old rows.
+  if (aIsHorizontal)
+  { 
+    if (aRowCount > mRowCount) {
+       row = MakeUnique<nsGridRow[]>(aRowCount);
+    } else {
+      for (int32_t i=0; i < mRowCount; i++)
+        mRows[i].Init(nullptr, false);
+
+      row = Move(mRows);
+    }
+  } else {
+    if (aRowCount > mColumnCount) {
+       row = MakeUnique<nsGridRow[]>(aRowCount);
+    } else {
+       for (int32_t i=0; i < mColumnCount; i++)
+         mColumns[i].Init(nullptr, false);
+
+       row = Move(mColumns);
+    }
+  }
+
+  // populate it if we can. If not it will contain only dynamic columns
+  if (aBox)
+  {
+    nsCOMPtr<nsIGridPart> monument = GetPartFromBox(aBox);
+    if (monument) {
+       monument->BuildRows(aBox, row.get());
+    }
+  }
+
+  return row;
+}
+
+
+/**
+ * Given the number of rows and columns. Build a cellmap
+ */
+UniquePtr<nsGridCell[]>
+nsGrid::BuildCellMap(int32_t aRows, int32_t aColumns)
+{
+  int32_t size = aRows*aColumns;
+  int32_t oldsize = mRowCount*mColumnCount;
+  if (size == 0) {
+    return nullptr;
+  }
+
+  if (size > oldsize) {
+    return MakeUnique<nsGridCell[]>(size);
+  }
+
+  // clear out cellmap
+  for (int32_t i=0; i < oldsize; i++) {
+    mCellMap[i].SetBoxInRow(nullptr);
+    mCellMap[i].SetBoxInColumn(nullptr);
+  }
+  return Move(mCellMap);
+}
+
+/** 
+ * Run through all the cells in the rows and columns and populate then with 2 cells. One from the row and one
+ * from the column
+ */
+void
+nsGrid::PopulateCellMap(nsGridRow* aRows, nsGridRow* aColumns, int32_t aRowCount, int32_t aColumnCount, bool aIsHorizontal)
+{
+  if (!aRows)
+    return;
+
+   // look through the columns
+  int32_t j = 0;
+
+  for(int32_t i=0; i < aRowCount; i++) 
+  {
+     nsIFrame* child = nullptr;
+     nsGridRow* row = &aRows[i];
+
+     // skip bogus rows. They have no cells
+     if (row->mIsBogus) 
+       continue;
+
+     child = row->mBox;
+     if (child) {
+       child = nsBox::GetChildXULBox(child);
+
+       j = 0;
+
+       while(child && j < aColumnCount)
+       {
+         // skip bogus column. They have no cells
+         nsGridRow* column = &aColumns[j];
+         if (column->mIsBogus) 
+         {
+           j++;
+           continue;
+         }
+
+         if (aIsHorizontal)
+           GetCellAt(j,i)->SetBoxInRow(child);
+         else
+           GetCellAt(i,j)->SetBoxInColumn(child);
+
+         child = nsBox::GetNextXULBox(child);
+
+         j++;
+       }
+     }
+  }
+}
+
+/**
+ * Run through the rows in the given box and mark them dirty so they 
+ * will get recalculated and get a layout.
+ */
+void 
+nsGrid::DirtyRows(nsIFrame* aRowBox, nsBoxLayoutState& aState)
+{
+  // make sure we prevent others from dirtying things.
+  mMarkingDirty = true;
+
+  // if the box is a grid part have it recursively hand it.
+  if (aRowBox) {
+    nsCOMPtr<nsIGridPart> part = GetPartFromBox(aRowBox);
+    if (part) 
+       part->DirtyRows(aRowBox, aState);
+  }
+
+  mMarkingDirty = false;
+}
+
+nsGridRow*
+nsGrid::GetColumnAt(int32_t aIndex, bool aIsHorizontal)
+{
+  return GetRowAt(aIndex, !aIsHorizontal);
+}
+
+nsGridRow*
+nsGrid::GetRowAt(int32_t aIndex, bool aIsHorizontal)
+{
+  RebuildIfNeeded();
+
+  if (aIsHorizontal) {
+    NS_ASSERTION(aIndex < mRowCount && aIndex >= 0, "Index out of range");
+    return &mRows[aIndex];
+  } else {
+    NS_ASSERTION(aIndex < mColumnCount && aIndex >= 0, "Index out of range");
+    return &mColumns[aIndex];
+  }
+}
+
+nsGridCell*
+nsGrid::GetCellAt(int32_t aX, int32_t aY)
+{
+  RebuildIfNeeded();
+
+  NS_ASSERTION(aY < mRowCount && aY >= 0, "Index out of range");
+  NS_ASSERTION(aX < mColumnCount && aX >= 0, "Index out of range");
+  return &mCellMap[aY*mColumnCount+aX];
+}
+
+int32_t
+nsGrid::GetExtraColumnCount(bool aIsHorizontal)
+{
+  return GetExtraRowCount(!aIsHorizontal);
+}
+
+int32_t
+nsGrid::GetExtraRowCount(bool aIsHorizontal)
+{
+  RebuildIfNeeded();
+
+  if (aIsHorizontal)
+    return mExtraRowCount;
+  else
+    return mExtraColumnCount;
+}
+
+
+/**
+ * These methods return the preferred, min, max sizes for a given row index.
+ * aIsHorizontal if aIsHorizontal is true. If you pass false you will get the inverse.
+ * As if you called GetPrefColumnSize(aState, index, aPref)
+ */
+nsSize
+nsGrid::GetPrefRowSize(nsBoxLayoutState& aState, int32_t aRowIndex, bool aIsHorizontal)
+{ 
+  nsSize size(0,0);
+  if (!(aRowIndex >=0 && aRowIndex < GetRowCount(aIsHorizontal)))
+    return size;
+
+  nscoord height = GetPrefRowHeight(aState, aRowIndex, aIsHorizontal);
+  SetLargestSize(size, height, aIsHorizontal);
+
+  return size;
+}
+
+nsSize
+nsGrid::GetMinRowSize(nsBoxLayoutState& aState, int32_t aRowIndex, bool aIsHorizontal)
+{ 
+  nsSize size(0,0);
+  if (!(aRowIndex >=0 && aRowIndex < GetRowCount(aIsHorizontal)))
+    return size;
+
+  nscoord height = GetMinRowHeight(aState, aRowIndex, aIsHorizontal);
+  SetLargestSize(size, height, aIsHorizontal);
+
+  return size;
+}
+
+nsSize
+nsGrid::GetMaxRowSize(nsBoxLayoutState& aState, int32_t aRowIndex, bool aIsHorizontal)
+{ 
+  nsSize size(NS_INTRINSICSIZE,NS_INTRINSICSIZE);
+  if (!(aRowIndex >=0 && aRowIndex < GetRowCount(aIsHorizontal)))
+    return size;
+
+  nscoord height = GetMaxRowHeight(aState, aRowIndex, aIsHorizontal);
+  SetSmallestSize(size, height, aIsHorizontal);
+
+  return size;
+}
+
+// static
+nsIGridPart*
+nsGrid::GetPartFromBox(nsIFrame* aBox)
+{
+  if (!aBox)
+    return nullptr;
+
+  nsBoxLayout* layout = aBox->GetXULLayoutManager();
+  return layout ? layout->AsGridPart() : nullptr;
+}
+
+nsMargin
+nsGrid::GetBoxTotalMargin(nsIFrame* aBox, bool aIsHorizontal)
+{
+  nsMargin margin(0,0,0,0);
+  // walk the boxes parent chain getting the border/padding/margin of our parent rows
+  
+  // first get the layour manager
+  nsIGridPart* part = GetPartFromBox(aBox);
+  if (part)
+    margin = part->GetTotalMargin(aBox, aIsHorizontal);
+
+  return margin;
+}
+
+/**
+ * The first and last rows can be affected by <rows> tags with borders or margin
+ * gets first and last rows and their indexes.
+ * If it fails because there are no rows then:
+ * FirstRow is nullptr
+ * LastRow is nullptr
+ * aFirstIndex = -1
+ * aLastIndex = -1
+ */
+void
+nsGrid::GetFirstAndLastRow(int32_t& aFirstIndex,
+                           int32_t& aLastIndex,
+                           nsGridRow*& aFirstRow,
+                           nsGridRow*& aLastRow,
+                           bool aIsHorizontal)
+{
+  aFirstRow = nullptr;
+  aLastRow = nullptr;
+  aFirstIndex = -1;
+  aLastIndex = -1;
+
+  int32_t count = GetRowCount(aIsHorizontal);
+
+  if (count == 0)
+    return;
+
+
+  // We could have collapsed columns either before or after our index.
+  // they should not count. So if we are the 5th row and the first 4 are
+  // collaped we become the first row. Or if we are the 9th row and
+  // 10 up to the last row are collapsed we then become the last.
+
+  // see if we are first
+  int32_t i;
+  for (i=0; i < count; i++)
+  {
+     nsGridRow* row = GetRowAt(i,aIsHorizontal);
+     if (!row->IsXULCollapsed()) {
+       aFirstIndex = i;
+       aFirstRow = row;
+       break;
+     }
+  }
+
+  // see if we are last
+  for (i=count-1; i >= 0; i--)
+  {
+     nsGridRow* row = GetRowAt(i,aIsHorizontal);
+     if (!row->IsXULCollapsed()) {
+       aLastIndex = i;
+       aLastRow = row;
+       break;
+     }
+
+  }
+}
+
+/**
+ * A row can have a top and bottom offset. Usually this is just the top and bottom border/padding.
+ * However if the row is the first or last it could be affected by the fact a column or columns could
+ * have a top or bottom margin. 
+ */
+void
+nsGrid::GetRowOffsets(int32_t aIndex, nscoord& aTop, nscoord& aBottom, bool aIsHorizontal)
+{
+
+  RebuildIfNeeded();
+
+  nsGridRow* row = GetRowAt(aIndex, aIsHorizontal);
+
+  if (row->IsOffsetSet()) 
+  {
+    aTop    = row->mTop;
+    aBottom = row->mBottom;
+    return;
+  }
+
+  // first get the rows top and bottom border and padding
+  nsIFrame* box = row->GetBox();
+
+  // add up all the padding
+  nsMargin margin(0,0,0,0);
+  nsMargin border(0,0,0,0);
+  nsMargin padding(0,0,0,0);
+  nsMargin totalBorderPadding(0,0,0,0);
+  nsMargin totalMargin(0,0,0,0);
+
+  // if there is a box and it's not bogus take its
+  // borders padding into account
+  if (box && !row->mIsBogus)
+  {
+    if (!box->IsXULCollapsed())
+    {
+       // get real border and padding. GetXULBorderAndPadding
+       // is redefined on nsGridRowLeafFrame. If we called it here
+       // we would be in finite recurson.
+       box->GetXULBorder(border);
+       box->GetXULPadding(padding);
+
+       totalBorderPadding += border;
+       totalBorderPadding += padding;
+     }
+
+     // if we are the first or last row
+     // take into account <rows> tags around us
+     // that could have borders or margins.
+     // fortunately they only affect the first
+     // and last row inside the <rows> tag
+
+     totalMargin = GetBoxTotalMargin(box, aIsHorizontal);
+  }
+
+  if (aIsHorizontal) {
+    row->mTop = totalBorderPadding.top;
+    row->mBottom = totalBorderPadding.bottom;
+    row->mTopMargin = totalMargin.top;
+    row->mBottomMargin = totalMargin.bottom;
+  } else {
+    row->mTop = totalBorderPadding.left;
+    row->mBottom = totalBorderPadding.right;
+    row->mTopMargin = totalMargin.left;
+    row->mBottomMargin = totalMargin.right;
+  }
+
+  // if we are the first or last row take into account the top and bottom borders
+  // of each columns. 
+
+  // If we are the first row then get the largest top border/padding in 
+  // our columns. If that's larger than the rows top border/padding use it.
+
+  // If we are the last row then get the largest bottom border/padding in 
+  // our columns. If that's larger than the rows bottom border/padding use it.
+  int32_t firstIndex = 0;
+  int32_t lastIndex = 0;
+  nsGridRow* firstRow = nullptr;
+  nsGridRow* lastRow = nullptr;
+  GetFirstAndLastRow(firstIndex, lastIndex, firstRow, lastRow, aIsHorizontal);
+
+  if (aIndex == firstIndex || aIndex == lastIndex) {
+    nscoord maxTop = 0;
+    nscoord maxBottom = 0;
+
+    // run through the columns. Look at each column
+    // pick the largest top border or bottom border
+    int32_t count = GetColumnCount(aIsHorizontal); 
+
+    for (int32_t i=0; i < count; i++)
+    {  
+      nsMargin totalChildBorderPadding(0,0,0,0);
+
+      nsGridRow* column = GetColumnAt(i,aIsHorizontal);
+      nsIFrame* box = column->GetBox();
+
+      if (box) 
+      {
+        // ignore collapsed children
+        if (!box->IsXULCollapsed())
+        {
+           // include the margin of the columns. To the row
+           // at this point border/padding and margins all added
+           // up to more needed space.
+           margin = GetBoxTotalMargin(box, !aIsHorizontal);
+           // get real border and padding. GetXULBorderAndPadding
+           // is redefined on nsGridRowLeafFrame. If we called it here
+           // we would be in finite recurson.
+           box->GetXULBorder(border);
+           box->GetXULPadding(padding);
+           totalChildBorderPadding += border;
+           totalChildBorderPadding += padding;
+           totalChildBorderPadding += margin;
+        }
+
+        nscoord top;
+        nscoord bottom;
+
+        // pick the largest top margin
+        if (aIndex == firstIndex) {
+          if (aIsHorizontal) {
+            top = totalChildBorderPadding.top;
+          } else {
+            top = totalChildBorderPadding.left;
+          }
+          if (top > maxTop)
+            maxTop = top;
+        } 
+
+        // pick the largest bottom margin
+        if (aIndex == lastIndex) {
+          if (aIsHorizontal) {
+            bottom = totalChildBorderPadding.bottom;
+          } else {
+            bottom = totalChildBorderPadding.right;
+          }
+          if (bottom > maxBottom)
+             maxBottom = bottom;
+        }
+
+      }
+    
+      // If the biggest top border/padding the columns is larger than this rows top border/padding
+      // the use it.
+      if (aIndex == firstIndex) {
+        if (maxTop > (row->mTop + row->mTopMargin))
+          row->mTop = maxTop - row->mTopMargin;
+      }
+
+      // If the biggest bottom border/padding the columns is larger than this rows bottom border/padding
+      // the use it.
+      if (aIndex == lastIndex) {
+        if (maxBottom > (row->mBottom + row->mBottomMargin))
+          row->mBottom = maxBottom - row->mBottomMargin;
+      }
+    }
+  }
+  
+  aTop    = row->mTop;
+  aBottom = row->mBottom;
+}
+
+/**
+ * These methods return the preferred, min, max coord for a given row index if
+ * aIsHorizontal is true. If you pass false you will get the inverse.
+ * As if you called GetPrefColumnHeight(aState, index, aPref).
+ */
+nscoord
+nsGrid::GetPrefRowHeight(nsBoxLayoutState& aState, int32_t aIndex, bool aIsHorizontal)
+{
+  RebuildIfNeeded();
+
+  nsGridRow* row = GetRowAt(aIndex, aIsHorizontal);
+
+  if (row->IsXULCollapsed())
+    return 0;
+
+  if (row->IsPrefSet()) 
+    return row->mPref;
+
+  nsIFrame* box = row->mBox;
+
+  // set in CSS?
+  if (box) 
+  {
+    bool widthSet, heightSet;
+    nsSize cssSize(-1, -1);
+    nsIFrame::AddXULPrefSize(box, cssSize, widthSet, heightSet);
+
+    row->mPref = GET_HEIGHT(cssSize, aIsHorizontal);
+
+    // yep do nothing.
+    if (row->mPref != -1)
+      return row->mPref;
+  }
+
+  // get the offsets so they are cached.
+  nscoord top;
+  nscoord bottom;
+  GetRowOffsets(aIndex, top, bottom, aIsHorizontal);
+
+  // is the row bogus? If so then just ask it for its size
+  // it should not be affected by cells in the grid. 
+  if (row->mIsBogus)
+  {
+     nsSize size(0,0);
+     if (box) 
+     {
+       size = box->GetXULPrefSize(aState);
+       nsBox::AddMargin(box, size);
+       nsGridLayout2::AddOffset(box, size);
+     }
+
+     row->mPref = GET_HEIGHT(size, aIsHorizontal);
+     return row->mPref;
+  }
+
+  nsSize size(0,0);
+
+  nsGridCell* child;
+
+  int32_t count = GetColumnCount(aIsHorizontal); 
+
+  for (int32_t i=0; i < count; i++)
+  {  
+    if (aIsHorizontal)
+     child = GetCellAt(i,aIndex);
+    else
+     child = GetCellAt(aIndex,i);
+
+    // ignore collapsed children
+    if (!child->IsXULCollapsed())
+    {
+      nsSize childSize = child->GetXULPrefSize(aState);
+
+      nsSprocketLayout::AddLargestSize(size, childSize, aIsHorizontal);
+    }
+  }
+
+  row->mPref = GET_HEIGHT(size, aIsHorizontal) + top + bottom;
+
+  return row->mPref;
+}
+
+nscoord
+nsGrid::GetMinRowHeight(nsBoxLayoutState& aState, int32_t aIndex, bool aIsHorizontal)
+{
+  RebuildIfNeeded();
+
+  nsGridRow* row = GetRowAt(aIndex, aIsHorizontal);
+
+  if (row->IsXULCollapsed())
+    return 0;
+
+  if (row->IsMinSet()) 
+    return row->mMin;
+
+  nsIFrame* box = row->mBox;
+
+  // set in CSS?
+  if (box) {
+    bool widthSet, heightSet;
+    nsSize cssSize(-1, -1);
+    nsIFrame::AddXULMinSize(aState, box, cssSize, widthSet, heightSet);
+
+    row->mMin = GET_HEIGHT(cssSize, aIsHorizontal);
+
+    // yep do nothing.
+    if (row->mMin != -1)
+      return row->mMin;
+  }
+
+  // get the offsets so they are cached.
+  nscoord top;
+  nscoord bottom;
+  GetRowOffsets(aIndex, top, bottom, aIsHorizontal);
+
+  // is the row bogus? If so then just ask it for its size
+  // it should not be affected by cells in the grid. 
+  if (row->mIsBogus)
+  {
+     nsSize size(0,0);
+     if (box) {
+       size = box->GetXULPrefSize(aState);
+       nsBox::AddMargin(box, size);
+       nsGridLayout2::AddOffset(box, size);
+     }
+
+     row->mMin = GET_HEIGHT(size, aIsHorizontal) + top + bottom;
+     return row->mMin;
+  }
+
+  nsSize size(0,0);
+
+  nsGridCell* child;
+
+  int32_t count = GetColumnCount(aIsHorizontal); 
+
+  for (int32_t i=0; i < count; i++)
+  {  
+    if (aIsHorizontal)
+     child = GetCellAt(i,aIndex);
+    else
+     child = GetCellAt(aIndex,i);
+
+    // ignore collapsed children
+    if (!child->IsXULCollapsed())
+    {
+      nsSize childSize = child->GetXULMinSize(aState);
+
+      nsSprocketLayout::AddLargestSize(size, childSize, aIsHorizontal);
+    }
+  }
+
+  row->mMin = GET_HEIGHT(size, aIsHorizontal);
+
+  return row->mMin;
+}
+
+nscoord
+nsGrid::GetMaxRowHeight(nsBoxLayoutState& aState, int32_t aIndex, bool aIsHorizontal)
+{
+  RebuildIfNeeded();
+
+  nsGridRow* row = GetRowAt(aIndex, aIsHorizontal);
+
+  if (row->IsXULCollapsed())
+    return 0;
+
+  if (row->IsMaxSet()) 
+    return row->mMax;
+
+  nsIFrame* box = row->mBox;
+
+  // set in CSS?
+  if (box) {
+    bool widthSet, heightSet;
+    nsSize cssSize(-1, -1);
+    nsIFrame::AddXULMaxSize(box, cssSize, widthSet, heightSet);
+
+    row->mMax = GET_HEIGHT(cssSize, aIsHorizontal);
+
+    // yep do nothing.
+    if (row->mMax != -1)
+      return row->mMax;
+  }
+
+  // get the offsets so they are cached.
+  nscoord top;
+  nscoord bottom;
+  GetRowOffsets(aIndex, top, bottom, aIsHorizontal);
+
+  // is the row bogus? If so then just ask it for its size
+  // it should not be affected by cells in the grid. 
+  if (row->mIsBogus)
+  {
+     nsSize size(NS_INTRINSICSIZE,NS_INTRINSICSIZE);
+     if (box) {
+       size = box->GetXULPrefSize(aState);
+       nsBox::AddMargin(box, size);
+       nsGridLayout2::AddOffset(box, size);
+     }
+
+     row->mMax = GET_HEIGHT(size, aIsHorizontal);
+     return row->mMax;
+  }
+
+  nsSize size(NS_INTRINSICSIZE,NS_INTRINSICSIZE);
+
+  nsGridCell* child;
+
+  int32_t count = GetColumnCount(aIsHorizontal); 
+
+  for (int32_t i=0; i < count; i++)
+  {  
+    if (aIsHorizontal)
+     child = GetCellAt(i,aIndex);
+    else
+     child = GetCellAt(aIndex,i);
+
+    // ignore collapsed children
+    if (!child->IsXULCollapsed())
+    {
+      nsSize min = child->GetXULMinSize(aState);
+      nsSize childSize = nsBox::BoundsCheckMinMax(min, child->GetXULMaxSize(aState));
+      nsSprocketLayout::AddLargestSize(size, childSize, aIsHorizontal);
+    }
+  }
+
+  row->mMax = GET_HEIGHT(size, aIsHorizontal) + top + bottom;
+
+  return row->mMax;
+}
+
+bool
+nsGrid::IsGrid(nsIFrame* aBox)
+{
+  nsIGridPart* part = GetPartFromBox(aBox);
+  if (!part)
+    return false;
+
+  nsGridLayout2* grid = part->CastToGridLayout();
+
+  if (grid)
+    return true;
+
+  return false;
+}
+
+/**
+ * This get the flexibilty of the row at aIndex. It's not trivial. There are a few
+ * things we need to look at. Specifically we need to see if any <rows> or <columns>
+ * tags are around us. Their flexibilty will affect ours.
+ */
+nscoord
+nsGrid::GetRowFlex(int32_t aIndex, bool aIsHorizontal)
+{
+  RebuildIfNeeded();
+
+  nsGridRow* row = GetRowAt(aIndex, aIsHorizontal);
+
+  if (row->IsFlexSet()) 
+    return row->mFlex;
+
+  nsIFrame* box = row->mBox;
+  row->mFlex = 0;
+
+  if (box) {
+
+    // We need our flex but a inflexible row could be around us. If so
+    // neither are we. However if its the row tag just inside the grid it won't 
+    // affect us. We need to do this for this case:
+    // <grid> 
+    //   <rows> 
+    //     <rows> // this is not flexible. So our children should not be flexible
+    //        <row flex="1"/>
+    //        <row flex="1"/>
+    //     </rows>
+    //        <row/>
+    //   </rows>
+    // </grid>
+    //
+    // or..
+    //
+    // <grid> 
+    //  <rows>
+    //   <rows> // this is not flexible. So our children should not be flexible
+    //     <rows flex="1"> 
+    //        <row flex="1"/>
+    //        <row flex="1"/>
+    //     </rows>
+    //        <row/>
+    //   </rows>
+    //  </row>
+    // </grid>
+
+
+    // So here is how it looks
+    //
+    // <grid>     
+    //   <rows>   // parentsParent
+    //     <rows> // parent
+    //        <row flex="1"/> 
+    //        <row flex="1"/>
+    //     </rows>
+    //        <row/>
+    //   </rows>
+    // </grid>
+
+    // so the answer is simple: 1) Walk our parent chain. 2) If we find
+    // someone who is not flexible and they aren't the rows immediately in
+    // the grid. 3) Then we are not flexible
+
+    box = GetScrollBox(box);
+    nsIFrame* parent = nsBox::GetParentXULBox(box);
+    nsIFrame* parentsParent=nullptr;
+
+    while(parent)
+    {
+      parent = GetScrollBox(parent);
+      parentsParent = nsBox::GetParentXULBox(parent);
+
+      // if our parents parent is not a grid
+      // the get its flex. If its 0 then we are
+      // not flexible.
+      if (parentsParent) {
+        if (!IsGrid(parentsParent)) {
+          nscoord flex = parent->GetXULFlex();
+          nsIFrame::AddXULFlex(parent, flex);
+          if (flex == 0) {
+            row->mFlex = 0;
+            return row->mFlex;
+          }
+        } else 
+          break;
+      }
+
+      parent = parentsParent;
+    }
+    
+    // get the row flex.
+    row->mFlex = box->GetXULFlex();
+    nsIFrame::AddXULFlex(box, row->mFlex);
+  }
+
+  return row->mFlex;
+}
+
+void
+nsGrid::SetLargestSize(nsSize& aSize, nscoord aHeight, bool aIsHorizontal)
+{
+  if (aIsHorizontal) {
+    if (aSize.height < aHeight)
+      aSize.height = aHeight;
+  } else {
+    if (aSize.width < aHeight)
+      aSize.width = aHeight;
+  }
+}
+
+void
+nsGrid::SetSmallestSize(nsSize& aSize, nscoord aHeight, bool aIsHorizontal)
+{
+  if (aIsHorizontal) {
+    if (aSize.height > aHeight)
+      aSize.height = aHeight;
+  } else {
+    if (aSize.width < aHeight)
+      aSize.width = aHeight;
+  }
+}
+
+int32_t 
+nsGrid::GetRowCount(int32_t aIsHorizontal)
+{
+  RebuildIfNeeded();
+
+  if (aIsHorizontal)
+    return mRowCount;
+  else
+    return mColumnCount;
+}
+
+int32_t 
+nsGrid::GetColumnCount(int32_t aIsHorizontal)
+{
+  return GetRowCount(!aIsHorizontal);
+}
+
+/*
+ * A cell in the given row or columns at the given index has had a child added or removed
+ */
+void 
+nsGrid::CellAddedOrRemoved(nsBoxLayoutState& aState, int32_t aIndex, bool aIsHorizontal)
+{
+  // TBD see if the cell will fit in our current row. If it will
+  // just add it in. 
+  // but for now rebuild everything.
+  if (mMarkingDirty)
+    return;
+
+  NeedsRebuild(aState);
+}
+
+/**
+ * A row or columns at the given index had been added or removed
+ */
+void 
+nsGrid::RowAddedOrRemoved(nsBoxLayoutState& aState, int32_t aIndex, bool aIsHorizontal)
+{
+  // TBD see if we have extra room in the table and just add the new row in
+  // for now rebuild the world
+  if (mMarkingDirty)
+    return;
+
+  NeedsRebuild(aState);
+}
+
+/*
+ * Scrollframes are tranparent. If this is given a scrollframe is will return the
+ * frame inside. If there is no scrollframe it does nothing.
+ */
+nsIFrame*
+nsGrid::GetScrolledBox(nsIFrame* aChild)
+{
+  // first see if it is a scrollframe. If so walk down into it and get the scrolled child
+      nsIScrollableFrame *scrollFrame = do_QueryFrame(aChild);
+      if (scrollFrame) {
+         nsIFrame* scrolledFrame = scrollFrame->GetScrolledFrame();
+         NS_ASSERTION(scrolledFrame,"Error no scroll frame!!");
+         return scrolledFrame;
+      }
+
+      return aChild;
+}
+
+/*
+ * Scrollframes are tranparent. If this is given a child in a scrollframe is will return the
+ * scrollframe ourside it. If there is no scrollframe it does nothing.
+ */
+nsIFrame*
+nsGrid::GetScrollBox(nsIFrame* aChild)
+{
+  if (!aChild)
+    return nullptr;
+
+  // get parent
+  nsIFrame* parent = nsBox::GetParentXULBox(aChild);
+
+  // walk up until we find a scrollframe or a part
+  // if it's a scrollframe return it.
+  // if it's a parent then the child passed does not
+  // have a scroll frame immediately wrapped around it.
+  while (parent) {
+    nsIScrollableFrame *scrollFrame = do_QueryFrame(parent);
+    // scrollframe? Yep return it.
+    if (scrollFrame)
+      return parent;
+
+    nsCOMPtr<nsIGridPart> parentGridRow = GetPartFromBox(parent);
+    // if a part then just return the child
+    if (parentGridRow) 
+      break;
+
+    parent = nsBox::GetParentXULBox(parent);
+  }
+
+  return aChild;
+}
+
+
+
+#ifdef DEBUG_grid
+void
+nsGrid::PrintCellMap()
+{
+  
+  printf("-----Columns------\n");
+  for (int x=0; x < mColumnCount; x++) 
+  {
+   
+    nsGridRow* column = GetColumnAt(x);
+    printf("%d(pf=%d, mn=%d, mx=%d) ", x, column->mPref, column->mMin, column->mMax);
+  }
+
+  printf("\n-----Rows------\n");
+  for (x=0; x < mRowCount; x++) 
+  {
+    nsGridRow* column = GetRowAt(x);
+    printf("%d(pf=%d, mn=%d, mx=%d) ", x, column->mPref, column->mMin, column->mMax);
+  }
+
+  printf("\n");
+  
+}
+#endif