Ruler column contributions are line based information areas that are normally shown in the vertical ruler area of the disassembly. a fully qualified identifier of the target extension point an optional identifier of the extension instance an optional name of the extension instance The specification of a ruler column contribution. The unique id of this column An optional name of the column, may be used in the user interface (e.g. in preference pages) An optional icon for the column. May be used in the user interface, for example on preference pages. The class implementing the column; must implement <code>org.eclipse.cdt.debug.ui.disassembly.rulers.IContributedRulerColumn</code> The default enablement state of this column. Controls whether toggling the visibility of this column operates on all targeted disassembly parts, or only the active disassembly part. If <i>true</i>, the ruler is added to all applicable parts when the user enables the column. Otherwise, the ruler is only added to the active disassembly part. Whether to include a "Show/Hide" menu entry for this column in the ruler context menu. Describes a disassembly part that the column is contributed to. The part id of the target disassembly part Describes a disassembly part class that the column is contributed to. Subclasses of the specified class are also targeted by this colum contribution. The fully qualified name of a class implementing IWorkbenchPart. The class does not need to be instantiatable. Describes the placement of this ruler column relative to other contributed columns. A column may request to be placed <em>before</em> or <em>after</em> other known columns (identified by their <tt>id</tt>). Columns that would end up at the same position are ordered by <em>gravity</em> (see below). If the ordering is contradicting or no ordering can be found that fulfills all placement requests, some placement requirements are dropped until the placement can be achieved. If a column does not fully specify its placement it will be placed at an arbitrary but consistent location. A floating point number between 0.0 and 1.0 that tells how close the column wants to be to the editor, where 0.0 means as far away as possible and 1.0 means as close as possible. After all <i>before</i> and <i>after</i> constraints are evaluated, columns that would end up at the same position are ordered by their <i>gravity</i> value. Requests placement before another column. The meaning of <i>before</i> is similar to the SWT.LEAD flag: In left-to-right environments, <i>before</i> means <i>to the left of</i>, in right-to-left environments, it means <i>to the right of</i>. The id of another <tt>rulerColumns</tt> contribution. Requests placement after another column. The meaning of <i>after</i> is similar to the SWT.TRAIL flag: In left-to-right environments, <i>after</i> means <i>to the right of</i>, in right-to-left environments, it means <i>to the left of</i>. The id of another <tt>rulerColumns</tt> contribution. All ruler column contributions must implement <code>org.eclipse.cdt.debug.ui.disassembly.rulers.IContributedRulerColumn</code>. Many contributors will find the supplied <code>org.eclipse.cdt.debug.ui.disassembly.rulers.AbstractContributedRulerColumn</code> useful which serves as super class for contributed ruler columns. Others might start off <code>org.eclipse.jface.text.source.AbstractRulerColumn</code> which takes over most painting and scrolling aspects of a line based column and can be extended at various granularity levels. Those subclassing the latter class will have to implement <code>org.eclipse.cdt.debug.ui.disassembly.rulers.IContributedRulerColumn</code> on their own by using <code>org.eclipse.cdt.debug.ui.disassembly.rulers.AbstractContributedRulerColumn</code> as template. Copyright (c) 2006, 20011 IBM Corporation and others.<br> This program and the accompanying materials are made available under the terms of the Eclipse Public License 2.0 which accompanies this distribution, and is available at <a href="http://www.eclipse.org/legal/epl-2.0/">https://www.eclipse.org/legal/epl-2.0/ t; t;SPDX-License-Identifier: EPL-2.0</a> The extension point is supported by the <tt>org.eclipse.cdt.debug.ui.disassembly.rulers</tt> package. <code>RulerColumnRegistry</code> gives access to all contributions, which in turn are described by <code>RulerColumnDescriptor</code> instances. 7.2