third_party/WebKit/Source/core/layout/LayoutButton.cpp

   1 /**
   2  * Copyright (C) 2005 Apple Computer, Inc.
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Library General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Library General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Library General Public License
  15  * along with this library; see the file COPYING.LIB.  If not, write to
  16  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  17  * Boston, MA 02110-1301, USA.
  18  *
  19  */
  20
  21 #include "config.h"
  22 #include "core/layout/LayoutButton.h"
  23
  24 namespace blink {
  25
  26 using namespace HTMLNames;
  27
  28 LayoutButton::LayoutButton(Element* element)
  29     : LayoutFlexibleBox(element)
  30     , m_inner(nullptr)
  31 {
  32 }
  33
  34 LayoutButton::~LayoutButton()
  35 {
  36 }
  37
  38 void LayoutButton::addChild(LayoutObject* newChild, LayoutObject* beforeChild)
  39 {
  40     if (!m_inner) {
  41         // Create an anonymous block.
  42         ASSERT(!firstChild());
  43         m_inner = createAnonymousBlock(style()->display());
  44         LayoutFlexibleBox::addChild(m_inner);
  45     }
  46
  47     m_inner->addChild(newChild, beforeChild);
  48 }
  49
  50 void LayoutButton::removeChild(LayoutObject* oldChild)
  51 {
  52     if (oldChild == m_inner || !m_inner) {
  53         LayoutFlexibleBox::removeChild(oldChild);
  54         m_inner = 0;
  55
  56     } else if (oldChild->parent() == this) {
  57         // We aren't the inner node, but we're getting removed from the button, this
  58         // can happen with things like scrollable area resizer's.
  59         LayoutFlexibleBox::removeChild(oldChild);
  60
  61     } else {
  62         m_inner->removeChild(oldChild);
  63     }
  64 }
  65
  66 void LayoutButton::updateAnonymousChildStyle(const LayoutObject& child, ComputedStyle& childStyle) const
  67 {
  68     ASSERT(!m_inner || &child == m_inner);
  69
  70     childStyle.setFlexGrow(1.0f);
  71     // min-width: 0; is needed for correct shrinking.
  72     childStyle.setMinWidth(Length(0, Fixed));
  73     // Use margin:auto instead of align-items:center to get safe centering, i.e.
  74     // when the content overflows, treat it the same as align-items: flex-start.
  75     childStyle.setMarginTop(Length());
  76     childStyle.setMarginBottom(Length());
  77     childStyle.setFlexDirection(style()->flexDirection());
  78     childStyle.setJustifyContent(style()->justifyContent());
  79     childStyle.setFlexWrap(style()->flexWrap());
  80     childStyle.setAlignItems(style()->alignItems());
  81     childStyle.setAlignContent(style()->alignContent());
  82 }
  83
  84 LayoutRect LayoutButton::controlClipRect(const LayoutPoint& additionalOffset) const
  85 {
  86     // Clip to the padding box to at least give content the extra padding space.
  87     LayoutRect rect(additionalOffset, size());
  88     rect.expand(borderInsets());
  89     return rect;
  90 }
  91
  92 int LayoutButton::baselinePosition(FontBaseline baseline, bool firstLine, LineDirectionMode direction, LinePositionMode linePositionMode) const
  93 {
  94     ASSERT(linePositionMode == PositionOnContainingLine);
  95     // We want to call the LayoutBlock version of firstLineBoxBaseline to
  96     // avoid LayoutFlexibleBox synthesizing a baseline that we don't want.
  97     // We use this check as a proxy for "are there any line boxes in this button"
  98     if (!hasLineIfEmpty() && LayoutBlock::firstLineBoxBaseline() == -1) {
  99         // To ensure that we have a consistent baseline when we have no children,
 100         // even when we have the anonymous LayoutBlock child, we calculate the
 101         // baseline for the empty case manually here.
 102         if (direction == HorizontalLine) {
 103             return marginTop() + size().height() - borderBottom() - paddingBottom() - horizontalScrollbarHeight();
 104         }
 105         return marginRight() + size().width() - borderLeft() - paddingLeft() - verticalScrollbarWidth();
 106     }
 107     return LayoutFlexibleBox::baselinePosition(baseline, firstLine, direction, linePositionMode);
 108 }
 109
 110
 111 // For compatibility with IE/FF we only clip overflow on input elements.
 112 bool LayoutButton::hasControlClip() const
 113 {
 114     return !isHTMLButtonElement(node());
 115 }
 116 } // namespace blink