layout/xul/nsListBoxLayout.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "nsListBoxLayout.h"
   7
   8 #include "nsListBoxBodyFrame.h"
   9 #include "nsBox.h"
  10 #include "nsBoxLayoutState.h"
  11 #include "nsIScrollableFrame.h"
  12 #include "nsIReflowCallback.h"
  13 #include "mozilla/dom/NameSpaceConstants.h"
  14 #include "nsGkAtoms.h"
  15 #include "nsContentUtils.h"
  16
  17 nsListBoxLayout::nsListBoxLayout() : nsGridRowGroupLayout()
  18 {
  19 }
  20
  21 ////////// nsBoxLayout //////////////
  22
  23 nsSize
  24 nsListBoxLayout::GetPrefSize(nsIFrame* aBox, nsBoxLayoutState& aBoxLayoutState)
  25 {
  26   nsSize pref = nsGridRowGroupLayout::GetPrefSize(aBox, aBoxLayoutState);
  27
  28   nsListBoxBodyFrame* frame = static_cast<nsListBoxBodyFrame*>(aBox);
  29   if (frame) {
  30     nscoord rowheight = frame->GetRowHeightAppUnits();
  31     pref.height = frame->GetRowCount() * rowheight;
  32     // Pad the height.
  33     nscoord y = frame->GetAvailableHeight();
  34     if (pref.height > y && y > 0 && rowheight > 0) {
  35       nscoord m = (pref.height-y)%rowheight;
  36       nscoord remainder = m == 0 ? 0 : rowheight - m;
  37       pref.height += remainder;
  38     }
  39     if (nsContentUtils::HasNonEmptyAttr(frame->GetContent(), kNameSpaceID_None,
  40                                         nsGkAtoms::sizemode)) {
  41       nscoord width = frame->ComputeIntrinsicISize(aBoxLayoutState);
  42       if (width > pref.width)
  43         pref.width = width;
  44     }
  45   }
  46   return pref;
  47 }
  48
  49 nsSize
  50 nsListBoxLayout::GetMinSize(nsIFrame* aBox, nsBoxLayoutState& aBoxLayoutState)
  51 {
  52   nsSize minSize = nsGridRowGroupLayout::GetMinSize(aBox, aBoxLayoutState);
  53
  54   nsListBoxBodyFrame* frame = static_cast<nsListBoxBodyFrame*>(aBox);
  55   if (frame) {
  56     nscoord rowheight = frame->GetRowHeightAppUnits();
  57     minSize.height = frame->GetRowCount() * rowheight;
  58     // Pad the height.
  59     nscoord y = frame->GetAvailableHeight();
  60     if (minSize.height > y && y > 0 && rowheight > 0) {
  61       nscoord m = (minSize.height-y)%rowheight;
  62       nscoord remainder = m == 0 ? 0 : rowheight - m;
  63       minSize.height += remainder;
  64     }
  65     if (nsContentUtils::HasNonEmptyAttr(frame->GetContent(), kNameSpaceID_None,
  66                                         nsGkAtoms::sizemode)) {
  67       nscoord width = frame->ComputeIntrinsicISize(aBoxLayoutState);
  68       if (width > minSize.width)
  69         minSize.width = width;
  70     }
  71   }
  72   return minSize;
  73 }
  74
  75 nsSize
  76 nsListBoxLayout::GetMaxSize(nsIFrame* aBox, nsBoxLayoutState& aBoxLayoutState)
  77 {
  78   nsSize maxSize = nsGridRowGroupLayout::GetMaxSize(aBox, aBoxLayoutState);
  79
  80   nsListBoxBodyFrame* frame = static_cast<nsListBoxBodyFrame*>(aBox);
  81   if (frame) {
  82     nscoord rowheight = frame->GetRowHeightAppUnits();
  83     maxSize.height = frame->GetRowCount() * rowheight;
  84     // Pad the height.
  85     nscoord y = frame->GetAvailableHeight();
  86     if (maxSize.height > y && y > 0 && rowheight > 0) {
  87       nscoord m = (maxSize.height-y)%rowheight;
  88       nscoord remainder = m == 0 ? 0 : rowheight - m;
  89       maxSize.height += remainder;
  90     }
  91   }
  92   return maxSize;
  93 }
  94
  95 NS_IMETHODIMP
  96 nsListBoxLayout::Layout(nsIFrame* aBox, nsBoxLayoutState& aState)
  97 {
  98   return LayoutInternal(aBox, aState);
  99 }
 100
 101
 102 /////////// nsListBoxLayout /////////////////////////
 103
 104 /**
 105  * Called to layout our our children. Does no frame construction
 106  */
 107 NS_IMETHODIMP
 108 nsListBoxLayout::LayoutInternal(nsIFrame* aBox, nsBoxLayoutState& aState)
 109 {
 110   int32_t redrawStart = -1;
 111
 112   // Get the start y position.
 113   nsListBoxBodyFrame* body = static_cast<nsListBoxBodyFrame*>(aBox);
 114   if (!body) {
 115     NS_ERROR("Frame encountered that isn't a listboxbody!");
 116     return NS_ERROR_FAILURE;
 117   }
 118
 119   nsMargin margin;
 120
 121   // Get our client rect.
 122   nsRect clientRect;
 123   aBox->GetClientRect(clientRect);
 124
 125   // Get the starting y position and the remaining available
 126   // height.
 127   nscoord availableHeight = body->GetAvailableHeight();
 128   nscoord yOffset = body->GetYPosition();
 129
 130   if (availableHeight <= 0) {
 131     bool fixed = (body->GetFixedRowSize() != -1);
 132     if (fixed)
 133       availableHeight = 10;
 134     else
 135       return NS_OK;
 136   }
 137
 138   // run through all our currently created children
 139   nsIFrame* box = nsBox::GetChildBox(body);
 140
 141   // if the reason is resize or initial we must relayout.
 142   nscoord rowHeight = body->GetRowHeightAppUnits();
 143
 144   while (box) {
 145     // If this box is dirty or if it has dirty children, we
 146     // call layout on it.
 147     nsRect childRect(box->GetRect());
 148     box->GetMargin(margin);
 149
 150     // relayout if we must or we are dirty or some of our children are dirty
 151     //   or the client area is wider than us
 152     // XXXldb There should probably be a resize check here too!
 153     if (NS_SUBTREE_DIRTY(box) || childRect.width < clientRect.width) {
 154       childRect.x = 0;
 155       childRect.y = yOffset;
 156       childRect.width = clientRect.width;
 157
 158       nsSize size = box->GetPrefSize(aState);
 159       body->SetRowHeight(size.height);
 160
 161       childRect.height = rowHeight;
 162
 163       childRect.Deflate(margin);
 164       box->SetBounds(aState, childRect);
 165       box->Layout(aState);
 166     } else {
 167       // if the child did not need to be relayed out. Then its easy.
 168       // Place the child by just grabbing its rect and adjusting the y.
 169       int32_t newPos = yOffset+margin.top;
 170
 171       // are we pushing down or pulling up any rows?
 172       // Then we may have to redraw everything below the moved
 173       // rows.
 174       if (redrawStart == -1 && childRect.y != newPos)
 175         redrawStart = newPos;
 176
 177       childRect.y = newPos;
 178       box->SetBounds(aState, childRect);
 179     }
 180
 181     // Ok now the available size gets smaller and we move the
 182     // starting position of the next child down some.
 183     nscoord size = childRect.height + margin.top + margin.bottom;
 184
 185     yOffset += size;
 186     availableHeight -= size;
 187
 188     box = nsBox::GetNextBox(box);
 189   }
 190
 191   // We have enough available height left to add some more rows
 192   // Since we can't do this during layout, we post a callback
 193   // that will be processed after the reflow completes.
 194   body->PostReflowCallback();
 195
 196   // if rows were pushed down or pulled up because some rows were added
 197   // before them then redraw everything under the inserted rows. The inserted
 198   // rows will automatically be redrawn because the were marked dirty on insertion.
 199   if (redrawStart > -1) {
 200     aBox->Redraw(aState);
 201   }
 202
 203   return NS_OK;
 204 }
 205
 206 // Creation Routines ///////////////////////////////////////////////////////////////////////
 207
 208 already_AddRefed<nsBoxLayout> NS_NewListBoxLayout()
 209 {
 210   nsRefPtr<nsBoxLayout> layout = new nsListBoxLayout();
 211   return layout.forget();
 212 }