layout/xul/nsStackLayout.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 //
   8 // Eric Vaughan
   9 // Netscape Communications
  10 //
  11 // See documentation in associated header file
  12 //
  13
  14 #include "nsStackLayout.h"
  15 #include "nsCOMPtr.h"
  16 #include "nsBoxLayoutState.h"
  17 #include "nsBox.h"
  18 #include "nsBoxFrame.h"
  19 #include "nsGkAtoms.h"
  20 #include "nsIContent.h"
  21 #include "nsNameSpaceManager.h"
  22
  23 using namespace mozilla;
  24
  25 nsBoxLayout* nsStackLayout::gInstance = nullptr;
  26
  27 #define SPECIFIED_LEFT (1 << eSideLeft)
  28 #define SPECIFIED_RIGHT (1 << eSideRight)
  29 #define SPECIFIED_TOP (1 << eSideTop)
  30 #define SPECIFIED_BOTTOM (1 << eSideBottom)
  31
  32 nsresult NS_NewStackLayout(nsCOMPtr<nsBoxLayout>& aNewLayout) {
  33   if (!nsStackLayout::gInstance) {
  34     nsStackLayout::gInstance = new nsStackLayout();
  35     NS_IF_ADDREF(nsStackLayout::gInstance);
  36   }
  37   // we have not instance variables so just return our static one.
  38   aNewLayout = nsStackLayout::gInstance;
  39   return NS_OK;
  40 }
  41
  42 /*static*/
  43 void nsStackLayout::Shutdown() { NS_IF_RELEASE(gInstance); }
  44
  45 nsStackLayout::nsStackLayout() {}
  46
  47 /*
  48  * Sizing: we are as wide as the widest child plus its left offset
  49  * we are tall as the tallest child plus its top offset.
  50  *
  51  * Only children which have -moz-stack-sizing set to stretch-to-fit
  52  * (the default) will be included in the size computations.
  53  */
  54
  55 nsSize nsStackLayout::GetXULPrefSize(nsIFrame* aBox, nsBoxLayoutState& aState) {
  56   nsSize prefSize(0, 0);
  57
  58   nsIFrame* child = nsBox::GetChildXULBox(aBox);
  59   while (child) {
  60     auto stackSizing = child->StyleXUL()->mStackSizing;
  61     if (stackSizing != StyleStackSizing::Ignore) {
  62       nsSize pref = child->GetXULPrefSize(aState);
  63
  64       AddMargin(child, pref);
  65       nsMargin offset;
  66       GetOffset(child, offset);
  67       pref.width += offset.LeftRight();
  68       pref.height += offset.TopBottom();
  69
  70       if (pref.width > prefSize.width &&
  71           stackSizing != StyleStackSizing::IgnoreHorizontal) {
  72         prefSize.width = pref.width;
  73       }
  74       if (pref.height > prefSize.height &&
  75           stackSizing != StyleStackSizing::IgnoreVertical) {
  76         prefSize.height = pref.height;
  77       }
  78     }
  79
  80     child = nsBox::GetNextXULBox(child);
  81   }
  82
  83   AddBorderAndPadding(aBox, prefSize);
  84
  85   return prefSize;
  86 }
  87
  88 nsSize nsStackLayout::GetXULMinSize(nsIFrame* aBox, nsBoxLayoutState& aState) {
  89   nsSize minSize(0, 0);
  90
  91   nsIFrame* child = nsBox::GetChildXULBox(aBox);
  92   while (child) {
  93     auto stackSizing = child->StyleXUL()->mStackSizing;
  94     if (stackSizing != StyleStackSizing::Ignore) {
  95       nsSize min = child->GetXULMinSize(aState);
  96
  97       AddMargin(child, min);
  98       nsMargin offset;
  99       GetOffset(child, offset);
 100       min.width += offset.LeftRight();
 101       min.height += offset.TopBottom();
 102
 103       if (min.width > minSize.width &&
 104           stackSizing != StyleStackSizing::IgnoreHorizontal) {
 105         minSize.width = min.width;
 106       }
 107       if (min.height > minSize.height &&
 108           stackSizing != StyleStackSizing::IgnoreVertical) {
 109         minSize.height = min.height;
 110       }
 111     }
 112
 113     child = nsBox::GetNextXULBox(child);
 114   }
 115
 116   AddBorderAndPadding(aBox, minSize);
 117
 118   return minSize;
 119 }
 120
 121 nsSize nsStackLayout::GetXULMaxSize(nsIFrame* aBox, nsBoxLayoutState& aState) {
 122   nsSize maxSize(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE);
 123
 124   nsIFrame* child = nsBox::GetChildXULBox(aBox);
 125   while (child) {
 126     auto stackSizing = child->StyleXUL()->mStackSizing;
 127     if (stackSizing != StyleStackSizing::Ignore) {
 128       nsSize min = child->GetXULMinSize(aState);
 129       nsSize max = child->GetXULMaxSize(aState);
 130
 131       max = nsBox::BoundsCheckMinMax(min, max);
 132
 133       AddMargin(child, max);
 134       nsMargin offset;
 135       GetOffset(child, offset);
 136       max.width += offset.LeftRight();
 137       max.height += offset.TopBottom();
 138
 139       if (max.width < maxSize.width &&
 140           stackSizing != StyleStackSizing::IgnoreHorizontal) {
 141         maxSize.width = max.width;
 142       }
 143       if (max.height < maxSize.height &&
 144           stackSizing != StyleStackSizing::IgnoreVertical) {
 145         maxSize.height = max.height;
 146       }
 147     }
 148
 149     child = nsBox::GetNextXULBox(child);
 150   }
 151
 152   AddBorderAndPadding(aBox, maxSize);
 153
 154   return maxSize;
 155 }
 156
 157 nscoord nsStackLayout::GetAscent(nsIFrame* aBox, nsBoxLayoutState& aState) {
 158   nscoord vAscent = 0;
 159
 160   nsIFrame* child = nsBox::GetChildXULBox(aBox);
 161   while (child) {
 162     nscoord ascent = child->GetXULBoxAscent(aState);
 163     nsMargin margin;
 164     child->GetXULMargin(margin);
 165     ascent += margin.top;
 166     if (ascent > vAscent) vAscent = ascent;
 167
 168     child = nsBox::GetNextXULBox(child);
 169   }
 170
 171   return vAscent;
 172 }
 173
 174 uint8_t nsStackLayout::GetOffset(nsIFrame* aChild, nsMargin& aOffset) {
 175   aOffset = nsMargin(0, 0, 0, 0);
 176
 177   // get the left, right, top and bottom offsets
 178
 179   // As an optimization, we cache the fact that we are not positioned to avoid
 180   // wasting time fetching attributes.
 181   if (aChild->IsXULBoxFrame() &&
 182       (aChild->GetStateBits() & NS_STATE_STACK_NOT_POSITIONED))
 183     return 0;
 184
 185   uint8_t offsetSpecified = 0;
 186   nsIContent* content = aChild->GetContent();
 187   if (content && content->IsElement()) {
 188     bool ltr = aChild->StyleVisibility()->mDirection == NS_STYLE_DIRECTION_LTR;
 189     nsAutoString value;
 190     nsresult error;
 191
 192     content->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::start, value);
 193     if (!value.IsEmpty()) {
 194       value.Trim("%");
 195       if (ltr) {
 196         aOffset.left =
 197             nsPresContext::CSSPixelsToAppUnits(value.ToInteger(&error));
 198         offsetSpecified |= SPECIFIED_LEFT;
 199       } else {
 200         aOffset.right =
 201             nsPresContext::CSSPixelsToAppUnits(value.ToInteger(&error));
 202         offsetSpecified |= SPECIFIED_RIGHT;
 203       }
 204     }
 205
 206     content->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::end, value);
 207     if (!value.IsEmpty()) {
 208       value.Trim("%");
 209       if (ltr) {
 210         aOffset.right =
 211             nsPresContext::CSSPixelsToAppUnits(value.ToInteger(&error));
 212         offsetSpecified |= SPECIFIED_RIGHT;
 213       } else {
 214         aOffset.left =
 215             nsPresContext::CSSPixelsToAppUnits(value.ToInteger(&error));
 216         offsetSpecified |= SPECIFIED_LEFT;
 217       }
 218     }
 219
 220     content->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::left, value);
 221     if (!value.IsEmpty()) {
 222       value.Trim("%");
 223       aOffset.left =
 224           nsPresContext::CSSPixelsToAppUnits(value.ToInteger(&error));
 225       offsetSpecified |= SPECIFIED_LEFT;
 226     }
 227
 228     content->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::right, value);
 229     if (!value.IsEmpty()) {
 230       value.Trim("%");
 231       aOffset.right =
 232           nsPresContext::CSSPixelsToAppUnits(value.ToInteger(&error));
 233       offsetSpecified |= SPECIFIED_RIGHT;
 234     }
 235
 236     content->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::top, value);
 237     if (!value.IsEmpty()) {
 238       value.Trim("%");
 239       aOffset.top = nsPresContext::CSSPixelsToAppUnits(value.ToInteger(&error));
 240       offsetSpecified |= SPECIFIED_TOP;
 241     }
 242
 243     content->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::bottom, value);
 244     if (!value.IsEmpty()) {
 245       value.Trim("%");
 246       aOffset.bottom =
 247           nsPresContext::CSSPixelsToAppUnits(value.ToInteger(&error));
 248       offsetSpecified |= SPECIFIED_BOTTOM;
 249     }
 250   }
 251
 252   if (!offsetSpecified && aChild->IsXULBoxFrame()) {
 253     // If no offset was specified at all, then we cache this fact to avoid
 254     // requerying CSS or the content model.
 255     aChild->AddStateBits(NS_STATE_STACK_NOT_POSITIONED);
 256   }
 257
 258   return offsetSpecified;
 259 }
 260
 261 NS_IMETHODIMP
 262 nsStackLayout::XULLayout(nsIFrame* aBox, nsBoxLayoutState& aState) {
 263   nsRect clientRect;
 264   aBox->GetXULClientRect(clientRect);
 265
 266   bool grow;
 267
 268   do {
 269     nsIFrame* child = nsBox::GetChildXULBox(aBox);
 270     grow = false;
 271
 272     while (child) {
 273       nsMargin margin;
 274       child->GetXULMargin(margin);
 275       nsRect childRect(clientRect);
 276       childRect.Deflate(margin);
 277
 278       if (childRect.width < 0) childRect.width = 0;
 279
 280       if (childRect.height < 0) childRect.height = 0;
 281
 282       nsRect oldRect(child->GetRect());
 283       bool sizeChanged = !oldRect.IsEqualEdges(childRect);
 284
 285       // only lay out dirty children or children whose sizes have changed
 286       if (sizeChanged || NS_SUBTREE_DIRTY(child)) {
 287         // add in the child's margin
 288         nsMargin margin;
 289         child->GetXULMargin(margin);
 290
 291         // obtain our offset from the top left border of the stack's content
 292         // box.
 293         nsMargin offset;
 294         uint8_t offsetSpecified = GetOffset(child, offset);
 295
 296         // Set the position and size based on which offsets have been specified:
 297         //   left only - offset from left edge, preferred width
 298         //   right only - offset from right edge, preferred width
 299         //   left and right - offset from left and right edges, width in between
 300         //   this neither - no offset, full width of stack
 301         // Vertical direction is similar.
 302         //
 303         // Margins on the child are also included in the edge offsets
 304         if (offsetSpecified) {
 305           nsSize min = child->GetXULMinSize(aState);
 306           nsSize max = child->GetXULMaxSize(aState);
 307           if (offsetSpecified & SPECIFIED_LEFT) {
 308             childRect.x = clientRect.x + offset.left + margin.left;
 309             if (offsetSpecified & SPECIFIED_RIGHT) {
 310               nscoord width =
 311                   clientRect.width - offset.LeftRight() - margin.LeftRight();
 312               childRect.width = clamped(width, min.width, max.width);
 313             } else {
 314               nscoord width = child->GetXULPrefSize(aState).width;
 315               childRect.width = clamped(width, min.width, max.width);
 316             }
 317           } else if (offsetSpecified & SPECIFIED_RIGHT) {
 318             nscoord width = child->GetXULPrefSize(aState).width;
 319             childRect.width = clamped(width, min.width, max.width);
 320             childRect.x = clientRect.XMost() - offset.right - margin.right -
 321                           childRect.width;
 322           }
 323
 324           if (offsetSpecified & SPECIFIED_TOP) {
 325             childRect.y = clientRect.y + offset.top + margin.top;
 326             if (offsetSpecified & SPECIFIED_BOTTOM) {
 327               nscoord height =
 328                   clientRect.height - offset.TopBottom() - margin.TopBottom();
 329               childRect.height = clamped(height, min.height, max.height);
 330             } else {
 331               nscoord height = child->GetXULPrefSize(aState).height;
 332               childRect.height = clamped(height, min.height, max.height);
 333             }
 334           } else if (offsetSpecified & SPECIFIED_BOTTOM) {
 335             nscoord height = child->GetXULPrefSize(aState).height;
 336             childRect.height = clamped(height, min.height, max.height);
 337             childRect.y = clientRect.YMost() - offset.bottom - margin.bottom -
 338                           childRect.height;
 339           }
 340         }
 341
 342         // Now place the child.
 343         child->SetXULBounds(aState, childRect);
 344
 345         // Flow the child.
 346         child->XULLayout(aState);
 347
 348         // Get the child's new rect.
 349         childRect = child->GetRect();
 350         childRect.Inflate(margin);
 351
 352         auto stackSizing = child->StyleXUL()->mStackSizing;
 353         if (stackSizing != StyleStackSizing::Ignore) {
 354           // Did the child push back on us and get bigger?
 355           if (offset.LeftRight() + childRect.width > clientRect.width &&
 356               stackSizing != StyleStackSizing::IgnoreHorizontal) {
 357             clientRect.width = childRect.width + offset.LeftRight();
 358             grow = true;
 359           }
 360
 361           if (offset.TopBottom() + childRect.height > clientRect.height &&
 362               stackSizing != StyleStackSizing::IgnoreVertical) {
 363             clientRect.height = childRect.height + offset.TopBottom();
 364             grow = true;
 365           }
 366         }
 367       }
 368
 369       child = nsBox::GetNextXULBox(child);
 370     }
 371   } while (grow);
 372
 373   // if some HTML inside us got bigger we need to force ourselves to
 374   // get bigger
 375   nsRect bounds(aBox->GetRect());
 376   nsMargin bp;
 377   aBox->GetXULBorderAndPadding(bp);
 378   clientRect.Inflate(bp);
 379
 380   if (clientRect.width > bounds.width || clientRect.height > bounds.height) {
 381     if (clientRect.width > bounds.width) bounds.width = clientRect.width;
 382     if (clientRect.height > bounds.height) bounds.height = clientRect.height;
 383
 384     aBox->SetXULBounds(aState, bounds);
 385   }
 386
 387   return NS_OK;
 388 }