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- static char help_text[] ="\n"
- "Introduction\n"
- "\n"
- " The OO-Browser Graphical Interface\n"
- "\n"
- " This program demonstrates a dynamic tree-drawing \n"
- " algorithm developed by Sven Moen. The algorithm is \n"
- " published in \"IEEE Software\", July 1990, pp. 21-28.\n"
- " If you desire more information than the description\n"
- " given below, see the above-referenced article. \n"
- "\n"
- " A number of the features mentioned herein are not\n"
- " included in this version of the program.\n"
- "\n"
- "Algorithm\n"
- "\n"
- " Unlike other algorithms, Moen's algorithm uses an \n"
- " explicit representation of node and subtree contours\n"
- " and it stores each contour as a polygon. \n"
- "\n"
- " Trees with nodes of any polygonal shape can be drawn\n"
- " compactly, and the data structure supports insert and\n"
- " delete operations on subtrees. The results are tidy\n"
- " trees and efficient relayouts when the tree changes.\n"
- "\n"
- " In the Layout step, the tree is traversed in depth-first\n"
- " fashion until the leaf nodes are reached. The contour\n"
- " of each leaf node is formed by creating a linked list of\n"
- " lines that wrap around the node's shape. This is the \n"
- " LayoutLeaf step. As the return trip is made back to the\n"
- " root, the contour of each interior node is formed by\n"
- " joining the individual contours of each child. This Join\n"
- " step involves a Merge step where the offset between\n"
- " two neighboring contours is computed to avoid overlap. \n"
- " Since the width of each subtree contour is known at\n"
- " each step, each interior node is centered over its\n"
- " children, and the subtree contour is extended to include\n"
- " the interior node. This is the AttachParent step.\n"
- "\n"
- " In a dynamic update operation (insert or delete), the\n"
- " algorithm reuses the contours not influenced by the\n"
- " change and updates them efficiently. When a given \n"
- " node changes, subtree contours at higher levels must\n"
- " be disassembled before the change. This is called\n"
- " the Unzip step, which call RuboutLeaf, Split, and\n"
- " DetachParent, all inverses of LayoutLeaf, Join, and\n"
- " AttachParent, respectively. After the change is made,\n"
- " the Zip step reassembles the contours by again calling\n"
- " Layout, Join, and AttachParent.\n"
- "\n"
- "User Interface\n"
- " \n"
- " This program offers an interactive environment for \n"
- " creating and updating trees of arbitrary size. Trees\n"
- " can be loaded from a file or created on-the-fly. You\n"
- " can also save trees, and specify various layout and\n"
- " animation options. Each feature is associated with \n"
- " a menu item which is explained in the next section.\n"
- "\n"
- " When invoking the program, you may specify a single\n"
- " argument indicating the name of a tree file. This file\n"
- " will be loaded upon startup. If you start the program\n"
- " without arguments, the canvas will be blank.\n"
- "\n"
- "Tree Menu\n"
- "\n"
- " New Tree... Create a new tree. You specify \n"
- " a new root, and the existing tree, \n"
- " if any, is deleted.\n"
- "\n"
- " Load Tree... Load a tree specification file.\n"
- " (see the File Format section)\n"
- "\n"
- " Save Tree... Save a tree specification file.\n"
- " (see the File Format section)\n"
- "\n"
- " Quit Exits the program.\n"
- "\n"
- "Layout Menu\n"
- "\n"
- " Layout Spacing...\n"
- " Displays a dialog that allows you\n"
- " to change the spacing between nodes\n"
- " on the same level and the spacing\n"
- " between levels. \n"
- "\n"
- " Align Nodes on Level\n"
- " Adds a constraint to the layout\n"
- " algorithm that forces all nodes\n"
- " on the same level to have the same\n"
- " x-position. This leads to truncation\n"
- " of nodes if necessary. The maximum\n"
- " node width is controlled by the\n"
- " Level Spacing. By default, this is\n"
- " disabled.\n"
- "\n"
- "Node Menu\n"
- "\n"
- " This popup menu is invoked by pressing and holding\n"
- " the left mouse button on a node. This menu offers\n"
- " several actions that can be performed on nodes.\n"
- "\n"
- " Add Child Add a child to the node. The new child\n"
- " is added after the bottommost child.\n"
- "\n"
- " Add Sibling Before\n"
- " Add a sibling before this node.\n"
- "\n"
- " Add Sibling After\n"
- " Add a sibling after this node.\n"
- "\n"
- " Collapse Node Collapses or expands the subtree\n"
- " Expand Node beginning at the specified node.\n"
- " This operation is similiar to a\n"
- " Delete operation, except that the\n"
- " subtree is preserved so that you\n"
- " can display it again. Collapsed\n"
- " nodes are marked with a gray box.\n"
- "\n"
- " Delete Node Delete the subtree beginning at the\n"
- " specified node.\n"
- "\n"
- "Tree File Format\n"
- "\n"
- " If you wish to load a file, you can load a file created\n"
- " by the OO-Browser with the {C-c d}, (br-xbr) command.\n"
- "\n"
- " Node labels are sequences of characters delimited by\n"
- " newlines or end-of-file. \n"
- "\n"
- " Files must begin with an OO-Browser Environment path\n"
- " name. The next line must be a label, which indicates the\n"
- " root node. Optionally, lists containing labels may\n"
- " follow. Each child label is indented two spaces more \n"
- " its parent. Lists of labels are nested to produce trees. \n"
- "\n"
- " For example, a three-level binary tree is as follows:\n"
- "\n"
- " ^^c++-^^~/OOBR\n"
- " root node level1\n"
- " level2-1\n"
- " level3-1\n"
- " level3-2\n"
- " level2-2\n"
- " level3-3\n"
- " level3-4\n"
- "\n"
- "X11 Resources\n"
- "\n"
- " Various settings in the program can be manipulated by \n"
- " using X11 resources, specified either on the command\n"
- " line or in a resource setting file. The supported \n"
- " resources are:\n"
- "\n"
- " tree.font: Sets the font of the label nodes.\n"
- " Default is \"fixed\".\n"
- "\n"
- " tree.backgroundColor:\n"
- " Sets the background color of the \n"
- " canvas. Default is \"white\".\n"
- "\n"
- " tree.treeColor: Sets the color of the displayed tree.\n"
- " Default is \"black\".\n"
- "\n"
- " tree.splitColor:\n"
- " Sets the color of split contours which\n"
- " appear during a dynamic update.\n"
- " Default is \"goldenrod\".\n"
- " \n"
- " tree.highlightColor:\n"
- " Sets the color of highlighted nodes.\n"
- " Default is \"OrangeRed\".\n"
- "\n"
- "Help\n"
- "\n"
- " If you are reading this, chances are that you found the\n"
- " Help button on the menubar. \n"
- "\n"
- "Author\n"
- " \n"
- " This program was written by Mark L. Stern during\n"
- " the summer of 1990. It was redone by Bob Weiner for\n"
- " use with the OO-Browser.\n"
- "\n"
- " Stephan Zachwieja contributed the double-buffering\n"
- " code used for smooth animations in this program.\n"
- "\n"
- " The other authors have permitted Bob Weiner to distribute\n"
- " the code freely as part of the OO-Browser.\n";
-