fune/layout/xul/grid/nsGridRowLayout.cpp

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 "nsGridRowLayout.h"
#include "nsBoxLayoutState.h"
#include "nsIScrollableFrame.h"
#include "nsBox.h"
#include "nsStackLayout.h"
#include "nsGrid.h"

nsGridRowLayout::nsGridRowLayout() : nsSprocketLayout() {}

nsGridRowLayout::~nsGridRowLayout() {}

void nsGridRowLayout::ChildrenInserted(nsIFrame* aBox, nsBoxLayoutState& aState,
                                       nsIFrame* aPrevBox,
                                       const nsFrameList::Slice& aNewChildren) {
  ChildAddedOrRemoved(aBox, aState);
}

void nsGridRowLayout::ChildrenAppended(nsIFrame* aBox, nsBoxLayoutState& aState,
                                       const nsFrameList::Slice& aNewChildren) {
  ChildAddedOrRemoved(aBox, aState);
}

void nsGridRowLayout::ChildrenRemoved(nsIFrame* aBox, nsBoxLayoutState& aState,
                                      nsIFrame* aChildList) {
  ChildAddedOrRemoved(aBox, aState);
}

void nsGridRowLayout::ChildrenSet(nsIFrame* aBox, nsBoxLayoutState& aState,
                                  nsIFrame* aChildList) {
  ChildAddedOrRemoved(aBox, aState);
}

nsIGridPart* nsGridRowLayout::GetParentGridPart(nsIFrame* aBox,
                                                nsIFrame** aParentBox) {
  // go up and find our parent gridRow. Skip and non gridRow
  // parents.
  *aParentBox = nullptr;

  // walk up through any scrollboxes
  aBox = nsGrid::GetScrollBox(aBox);

  // get the parent
  if (aBox) aBox = nsBox::GetParentXULBox(aBox);

  if (aBox) {
    nsIGridPart* parentGridRow = nsGrid::GetPartFromBox(aBox);
    if (parentGridRow && parentGridRow->CanContain(this)) {
      *aParentBox = aBox;
      return parentGridRow;
    }
  }

  return nullptr;
}

nsGrid* nsGridRowLayout::GetGrid(nsIFrame* aBox, int32_t* aIndex,
                                 nsGridRowLayout* aRequestor) {
  if (aRequestor == nullptr) {
    nsIFrame* parentBox;  // nsIFrame is implemented by nsIFrame and is not
                          // refcounted.
    nsIGridPart* parent = GetParentGridPart(aBox, &parentBox);
    if (parent) return parent->GetGrid(parentBox, aIndex, this);
    return nullptr;
  }

  int32_t index = -1;
  nsIFrame* child = nsBox::GetChildXULBox(aBox);
  int32_t count = 0;
  while (child) {
    // if there is a scrollframe walk inside it to its child
    nsIFrame* childBox = nsGrid::GetScrolledBox(child);

    nsBoxLayout* layout = childBox->GetXULLayoutManager();
    nsIGridPart* gridRow = nsGrid::GetPartFromBox(childBox);
    if (gridRow) {
      if (layout == aRequestor) {
        index = count;
        break;
      }
      count += gridRow->GetRowCount();
    } else
      count++;

    child = nsBox::GetNextXULBox(child);
  }

  // if we didn't find ourselves then the tree isn't properly formed yet
  // this could happen during initial construction so lets just
  // fail.
  if (index == -1) {
    *aIndex = -1;
    return nullptr;
  }

  (*aIndex) += index;

  nsIFrame*
      parentBox;  // nsIFrame is implemented by nsIFrame and is not refcounted.
  nsIGridPart* parent = GetParentGridPart(aBox, &parentBox);
  if (parent) return parent->GetGrid(parentBox, aIndex, this);

  return nullptr;
}

nsMargin nsGridRowLayout::GetTotalMargin(nsIFrame* aBox, bool aIsHorizontal) {
  // get our parents margin
  nsMargin margin(0, 0, 0, 0);
  nsIFrame* parent = nullptr;
  nsIGridPart* part = GetParentGridPart(aBox, &parent);
  if (part && parent) {
    // if we are the first or last child walk upward and add margins.

    // make sure we check for a scrollbox
    aBox = nsGrid::GetScrollBox(aBox);

    // see if we have a next to see if we are last
    nsIFrame* next = nsBox::GetNextXULBox(aBox);

    // get the parent first child to see if we are first
    nsIFrame* child = nsBox::GetChildXULBox(parent);

    margin = part->GetTotalMargin(parent, aIsHorizontal);

    // if first or last
    if (child == aBox || next == nullptr) {
      // if it's not the first child remove the top margin
      // we don't need it.
      if (child != aBox) {
        if (aIsHorizontal)
          margin.top = 0;
        else
          margin.left = 0;
      }

      // if it's not the last child remove the bottom margin
      // we don't need it.
      if (next != nullptr) {
        if (aIsHorizontal)
          margin.bottom = 0;
        else
          margin.right = 0;
      }
    }
  }

  // add ours to it.
  nsMargin ourMargin;
  aBox->GetXULMargin(ourMargin);
  margin += ourMargin;

  return margin;
}

NS_IMPL_ADDREF_INHERITED(nsGridRowLayout, nsBoxLayout)
NS_IMPL_RELEASE_INHERITED(nsGridRowLayout, nsBoxLayout)

NS_INTERFACE_MAP_BEGIN(nsGridRowLayout)
  NS_INTERFACE_MAP_ENTRY(nsIGridPart)
  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIGridPart)
NS_INTERFACE_MAP_END_INHERITING(nsBoxLayout)