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diff --git a/old/dw/html/dw-stacking-context.html b/old/dw/html/dw-stacking-context.html new file mode 100644 index 0000000..7693294 --- /dev/null +++ b/old/dw/html/dw-stacking-context.html @@ -0,0 +1,102 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> +<html xmlns="http://www.w3.org/1999/xhtml"> +<head> +<meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/> +<meta http-equiv="X-UA-Compatible" content="IE=9"/> +<meta name="generator" content="Doxygen 1.8.8"/> +<title>Dillo: Handling stacking contexts</title> +<link href="tabs.css" rel="stylesheet" type="text/css"/> +<script type="text/javascript" src="https://www.dillo.org/dw/html/jquery.js"></script> +<script type="text/javascript" src="dynsections.js"></script> +<link href="doxygen.css" rel="stylesheet" type="text/css" /> +</head> +<body> +<div id="top"><!-- do not remove this div, it is closed by doxygen! --> +<div id="titlearea"> +<table cellspacing="0" cellpadding="0"> + <tbody> + <tr style="height: 56px;"> + <td style="padding-left: 0.5em;"> + <div id="projectname">Dillo + </div> + </td> + </tr> + </tbody> +</table> +</div> +<!-- end header part --> +<!-- Generated by Doxygen 1.8.8 --> + <div id="navrow1" class="tabs"> + <ul class="tablist"> + <li><a href="index.html"><span>Main Page</span></a></li> + <li class="current"><a href="pages.html"><span>Related Pages</span></a></li> + <li><a href="namespaces.html"><span>Namespaces</span></a></li> + <li><a href="annotated.html"><span>Classes</span></a></li> + <li><a href="files.html"><span>Files</span></a></li> + </ul> + </div> +</div><!-- top --> +<div class="header"> + <div class="headertitle"> +<div class="title">Handling stacking contexts </div> </div> +</div><!--header--> +<div class="contents"> +<div class="textblock"><h1>Stacking Context and <a class="el" href="classdw_1_1core_1_1StackingContextMgr.html" title="See Handling stacking contexts. ">dw::core::StackingContextMgr</a> </h1> +<p>For the definition of stacking contexts, see CSS 2.1 specification,</p> +<ul> +<li><a href="http://www.w3.org/TR/CSS2/visuren.html#z-index">section 9.9.1: Specifying the stack level: the 'z-index' property</a> and</li> +<li><a href="http://www.w3.org/TR/CSS2/zindex.html">appendix E</a>.</li> +</ul> +<p>A widget establishes a stacking context when it is positioned and its style value of <em>z-index</em> is different from <em>auto</em> (see <a class="el" href="classdw_1_1core_1_1StackingContextMgr.html#aa000c80d14e002fe5a45bd8e994d6670">dw::core::StackingContextMgr::isEstablishingStackingContext</a>). In this case, it is assigned an instance of <a class="el" href="classdw_1_1core_1_1StackingContextMgr.html" title="See Handling stacking contexts. ">dw::core::StackingContextMgr</a>, which has also access to the widgets establishing the child contexts.</p> +<h1>Stacking Order </h1> +<p>The stacking order influences</p> +<ol type="1"> +<li>the order in which child widgets are drawn (<a class="el" href="classdw_1_1core_1_1Widget.html#a2e7d05212aabad32824fd577fb7e3dd7">dw::core::Widget::draw</a>), and</li> +<li>the order in which mouse events are dispatched to child widgets (<a class="el" href="classdw_1_1core_1_1Widget.html#aa4eac09454c63d9dc7a8d6a322e7998a">dw::core::Widget::getWidgetAtPoint</a>).</li> +</ol> +<p>The first is done from bottom to top, the latter from top to bottom.</p> +<p>I'm here referring to the simplified description in <a href="http://www.w3.org/TR/CSS2/visuren.html#z-index">section 9.9.1</a>. The table shows a recommended order for the implementations of <a class="el" href="classdw_1_1core_1_1Widget.html#a2e7d05212aabad32824fd577fb7e3dd7">dw::core::Widget::draw</a> and <a class="el" href="classdw_1_1core_1_1Widget.html#aa4eac09454c63d9dc7a8d6a322e7998a">dw::core::Widget::getWidgetAtPoint</a> (for the latter, read from bottom to top):</p> +<table class="doxtable"> +<tr> +<th>CSS specification </th><th>Drawing </th><th>Mouse events </th></tr> +<tr> +<td><em>1. the background and borders of the element forming the stacking context.</em> </td><td><a class="el" href="classdw_1_1core_1_1Widget.html#aef48f52db329c961daed586d291461d5" title="Draw borders and background of a widget part, which allocation is given by (x, y, width...">dw::core::Widget::drawBox</a> </td><td>Nothing necessary. </td></tr> +<tr> +<td><em>2. the child stacking contexts with negative stack levels (most negative first).</em> </td><td><a class="el" href="classdw_1_1core_1_1StackingContextMgr.html#a8a31dad74e5886a3c0a200fc327463a3">dw::core::StackingContextMgr::drawBottom</a> (when defined) </td><td><a class="el" href="classdw_1_1core_1_1StackingContextMgr.html#ae002cba1d7e7d67c8d4a5cc802dfd6cc">dw::core::StackingContextMgr::getBottomWidgetAtPoint</a> (when defined) </td></tr> +<tr> +<td><p class="starttd"><em>3. the in-flow, non-inline-level, non-positioned descendants.</em></p> +<p class="endtd"></p> +</td><td rowspan="4"><p class="starttd">When (i) widget specific content is drawn, then (ii) <a class="el" href="classdw_1_1oof_1_1OOFAwareWidget.html#af00de9105bb5ba2a0f88c3c8daba20a0">dw::oof::OOFAwareWidget::drawOOF</a> is called, this will have this effect:</p> +<ol type="1"> +<li>all in-flow elements are drawn,</li> +<li>floats are drawn and</li> +<li>positioned elements with <em>z-index: auto</em> are drawn (latter two done by <a class="el" href="classdw_1_1oof_1_1OOFAwareWidget.html#af00de9105bb5ba2a0f88c3c8daba20a0">dw::oof::OOFAwareWidget::drawOOF</a>, in this order).</li> +</ol> +<p>This order differs from the specified order, but since floats and in-flow elements do not overlap, this difference has no effect.</p> +<p>Drawing in-line elements, floats and positioned elements with <em>z-index: auto</em> and should avoid duplicate calls: Widgets drawn by <a class="el" href="classdw_1_1core_1_1StackingContextMgr.html#a8a31dad74e5886a3c0a200fc327463a3">dw::core::StackingContextMgr::drawBottom</a> and by <a class="el" href="classdw_1_1core_1_1StackingContextMgr.html#a3d4efbb7fe900fe5a0f734d534929e7c">dw::core::StackingContextMgr::drawTop</a> should be excluded here. This can be tested with <a class="el" href="classdw_1_1core_1_1StackingContextMgr.html#a64309f6cf7debcb812b3bf909c098b6e">dw::core::StackingContextMgr::handledByStackingContextMgr</a>.</p> +<p class="endtd"></p> +</td><td rowspan="4"><p class="starttd">Likewise, the implementation should (i) test <a class="el" href="classdw_1_1oof_1_1OOFAwareWidget.html#a26b40025daf7ae24d748b967d74a6f14">dw::oof::OOFAwareWidget::getWidgetOOFAtPoint</a>, and (ii) search through the chilren. Also, duplicate calls should be avoided using <a class="el" href="classdw_1_1core_1_1StackingContextMgr.html#a64309f6cf7debcb812b3bf909c098b6e">dw::core::StackingContextMgr::handledByStackingContextMgr</a>.</p> +<p>There are already the implementations <a class="el" href="classdw_1_1core_1_1Widget.html#aa4eac09454c63d9dc7a8d6a322e7998a">dw::core::Widget::getWidgetAtPoint</a> (ignoring <a class="el" href="classdw_1_1oof_1_1OutOfFlowMgr.html" title="Represents additional data for OOF containers. ">dw::oof::OutOfFlowMgr</a>) and <a class="el" href="classdw_1_1oof_1_1OOFAwareWidget.html#a6483f089749d7b31b3fe238d8087e3ac">dw::oof::OOFAwareWidget::getWidgetAtPoint</a> (including <a class="el" href="classdw_1_1oof_1_1OutOfFlowMgr.html" title="Represents additional data for OOF containers. ">dw::oof::OutOfFlowMgr</a>).</p> +<p class="endtd"></p> +</td></tr> +<tr> +<td><em>4. the non-positioned floats.</em> </td></tr> +<tr> +<td><em>5. the in-flow, inline-level, non-positioned descendants, including inline tables and inline blocks.</em> </td></tr> +<tr> +<td>(What about positioned elements with <em>z-index: auto</em>? Seems to be missing in <a href="http://www.w3.org/TR/CSS2/visuren.html#z-index">section 9.9.1</a>, but mentioned in <a href="http://www.w3.org/TR/CSS2/zindex.html">appendix E</a>, item 8. </td></tr> +<tr> +<td><em>6. the child stacking contexts with stack level 0 and the positioned descendants with stack level 0.</em> </td><td rowspan="2"><a class="el" href="classdw_1_1core_1_1StackingContextMgr.html#a3d4efbb7fe900fe5a0f734d534929e7c">dw::core::StackingContextMgr::drawTop</a> (when defined) </td><td rowspan="2"><a class="el" href="classdw_1_1core_1_1StackingContextMgr.html#ac7e560cd0c894f1b587bbebd253a8f3a">dw::core::StackingContextMgr::getTopWidgetAtPoint</a> (when defined) </td></tr> +<tr> +<td><em>7. the child stacking contexts with positive stack levels (least positive first).</em> </td></tr> +</table> +<p>Note: This is not quite in conformance with the specification: this description refers to any widget, not only widgets establishing a stacking context. Does this make a difference? </p> +</div></div><!-- contents --> +<!-- start footer part --> +<hr class="footer"/><address class="footer"><small> +Generated on Sat May 28 2016 11:47:43 for Dillo by  <a href="http://www.doxygen.org/index.html"> +<img class="footer" src="doxygen.png" alt="doxygen"/> +</a> 1.8.8 +</small></address> +</body> +</html> |