| 1 | WCKER tree editing behaviour spec. v0.2 2005-03-17 |
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| 2 | |
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| 3 | Preable |
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| 4 | ======= |
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| 5 | Some of the decisions here are sub-optimal so far as usability goes, but they're a solid place to start and to improve upon in the next version of WCKER. |
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| 6 | Suggestions to improve clarity are needed and would be apprieciated. |
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| 7 | |
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| 8 | |
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| 9 | |
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| 10 | |
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| 11 | Relationship to Reload |
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| 12 | ====================== |
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| 13 | Where possible and relevant, WCKER tree editing should follow that of Reload tree editing. However, differences in the approaches taken by Reload and WCKER will require some divergence. |
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| 14 | |
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| 15 | To put it another way: we should do what Reload does, unless we've got a good reason not to. |
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| 16 | |
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| 17 | |
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| 18 | |
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| 19 | |
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| 20 | The tree |
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| 21 | ======== |
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| 22 | * The tree may contain container items (e.g. units) and pages. |
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| 23 | * At its most permissive, all containers in the tree may hold pages and other containers. |
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| 24 | * More restrictive configurations may be defined in the structure section of the wizard.wsi file. |
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| 25 | * The restrictions can limit the contents of containers at specific depths to only pages, or only containers. |
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| 26 | |
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| 27 | |
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| 28 | |
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| 29 | |
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| 30 | The buttons |
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| 31 | =========== |
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| 32 | There are three groups of buttons relating to editing the tree: |
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| 33 | 1) The heirarchical tree widget and editing icons |
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| 34 | 2) The Input fields (e.g. title, author, course aim) |
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| 35 | 3) The Previous item and Next item buttons |
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| 36 | |
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| 37 | (see http://waterbuck.conted.ox.ac.uk/cgi-bin/trac.cgi/wiki/GuiPrototype#Customise-course-step-course-level) |
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| 38 | |
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| 39 | |
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| 40 | |
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| 41 | For 1) |
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| 42 | ~~~~~~ |
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| 43 | (Ignoring drag-and-drop as we probably don't have time to implement it.) |
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| 44 | There are two major parts to this group: the tree and the editing icon buttons. |
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| 45 | |
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| 46 | _The tree_ |
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| 47 | |
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| 48 | The tree is a heirarchy of nodes representing containers and pages, with exactly one root node. The root node relates to the "organization" element on the IMSCP manifest file. |
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| 49 | |
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| 50 | Any one of the tree's nodes can be selected at a time. Doing so creates a "selection context" which will affect what actions are available to the user. (There may or may not be code forming selection context explicitly, that's an implementation detail.) |
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| 51 | |
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| 52 | A selection context describes: |
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| 53 | * What node is selected (there must be a way to relate that to the part of the IMS manifest it represents) |
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| 54 | * Which of the editing icons' actions can be performed on the node, determined by: |
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| 55 | |
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| 56 | a) Whether the node can accept container nodes as children. True if all of the following are true: |
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| 57 | * node is a container |
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| 58 | * the wizard.wsi structure section allows child containers |
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| 59 | |
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| 60 | b) Whether the node can accept page nodes as children. True if all of the following are true: |
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| 61 | * node is a container |
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| 62 | * the wizard.wsi structure section allows child pagess |
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| 63 | |
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| 64 | c) Whether the node can be deleted. True if all of the following are true: |
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| 65 | * node is not the root node |
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| 66 | * node is not marked as indestructable in the wizard.wsi structure section (not implemented) |
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| 67 | |
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| 68 | d) Whether the node can moved up. True if all of the following are true: |
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| 69 | * node is not the root node |
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| 70 | * node is not the first child of the root node |
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| 71 | * node is not the first instance of that type of node at that tree depth |
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| 72 | |
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| 73 | e) Whether the node can moved down. True if all of the following are true: |
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| 74 | * node is not the root node |
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| 75 | * node is not the last node in a depth first linearisation of the tree |
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| 76 | * node is not the last instance of that type of node at that tree depth |
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| 77 | |
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| 78 | NB. Adding siblings will not be allowed in this version of WCKER. |
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| 79 | |
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| 80 | |
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| 81 | _The editing icon buttons_ |
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| 82 | |
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| 83 | These buttons are enabled/disabled according to the selection context. |
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| 84 | |
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| 85 | Behaviour when activated: |
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| 86 | * Add container |
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| 87 | * If only one type of container may be legally inserted as a child of the selected node, it is inserted as the last child of the node. |
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| 88 | * If there are more than one type of container item which may be legally inserted as a child of the selected node, a list of allowed containers should popup, allowing the user to choose which type to add. On selection of a container type, it is inserted as the last child of the node. (The initial version of WCKER may not include this functionality.) |
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| 89 | |
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| 90 | * Delete container |
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| 91 | * Removes the container and all its childeren from the tree. |
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| 92 | |
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| 93 | * Add Page |
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| 94 | * Adds a page as the last child of the selected node. |
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| 95 | |
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| 96 | * Delete Page |
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| 97 | * Removes the page from the tree. |
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| 98 | |
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| 99 | * Move selected up |
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| 100 | * Moves the selected item to the first available preceding location. Non-exhaustive examples: |
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| 101 | a) A page with another page immediately preceding it - would moved above the preceding page (or be swapped with it, depending on how you think about it). |
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| 102 | b) A page with no sibling pages immediately preceding it, where pages are legal at any point preceeding the page - would be moved to the first legal point found when looking backwards through a depth first linearisation of the tree, starting at the selected node. |
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| 103 | c) A container with another container immediately preceding it - would moved above the preceding container (or be swapped with it, depending on how you think about it). |
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| 104 | |
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| 105 | |
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| 106 | * Move selected down |
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| 107 | * Moves the selected item to the first available following location. Non-exhaustive examples: |
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| 108 | a) A page with another page immediately following it - would moved below the preceding page (or be swapped with it, depending on how you think about it). |
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| 109 | b) A page with no sibling pages immediately following it, where pages are legal at any point following the page - would be moved to the first legal point found when looking forwards through a depth first linearisation of the tree, starting at the selected node. |
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| 110 | c) A container with another container immediately following it - would moved below the preceding container (or be swapped with it, depending on how you think about it). |
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| 111 | |
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| 112 | NB: The move up and move down actions keep a node as the same node type, at the same hierarchical depth. A later version of WCKER might include functionality to promote/demote nodes up and down the tree, and to convert between node types. |
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| 113 | |
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| 114 | |
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| 115 | |
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| 116 | For 2) |
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| 117 | ~~~~~~ |
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| 118 | A number of fields used to input data relating to the selected node. |
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| 119 | When the Title field is edited, the changes should appear in the corresponding part of the tree widget (on keypress). |
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| 120 | No fields other than the title are represented on the tree widget, so changes to them are of no consequence to the tree widget. |
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| 121 | |
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| 122 | |
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| 123 | |
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| 124 | For 3) |
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| 125 | ~~~~~~ |
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| 126 | These buttons should change the node selected in the tree widget, stepping back and forth through the course structure hierarchy using a depth first linearisation. |
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| 127 | Activating the "Previous item" should move the selection one node back (ie up the screen). |
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| 128 | Activating the "Next item" should move the selection one node forward (ie down the screen). |
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| 129 | |
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| 130 | "Previous item" is disabled if the selected node is the root node. |
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| 131 | "Next item" is disabled if the selected node is the last node in the linearisation. |
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| 132 | |
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| 133 | |
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| 134 | |
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| 135 | |
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