1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
|
<html lang="en">
<head>
<title>ECB - the Emacs Code Browser</title>
<meta http-equiv="Content-Type" content="text/html">
<meta name=description content="ECB - the Emacs Code Browser">
<meta name=generator content="makeinfo 4.2">
<link href="http://www.gnu.org/software/texinfo/" rel=generator-home>
</head>
<body>
<p>
Node:<a name="Introduction">Introduction</a>,
Next:<a rel=next accesskey=n href="A-new-tree-buffer.html#A%20new%20tree-buffer">A new tree-buffer</a>,
Previous:<a rel=previous accesskey=p href="tree-buffer.html#tree-buffer">tree-buffer</a>,
Up:<a rel=up accesskey=u href="tree-buffer.html#tree-buffer">tree-buffer</a>
<hr><br>
<h4>General description of tree-buffers</h4>
<p>This subchapter is a general introduction in the main concepts of a
tree-buffer.
<h5>What is a tree-buffer?</h5>
<p>A <dfn>tree-buffer</dfn> is meant to display certain informations (e.g. a
directory-tree) in a tree-structure consisting of <dfn>tree-nodes</dfn>.
Every line in a tree-buffer displays exactly one tree-node. Each node
has exactly one parent-node and can have any arbitrary number of
<dfn>children</dfn>-nodes. If a tree-node has no children then it is called
a <dfn>leaf</dfn>. A tree-node contains several "slots" wheras the most
important ones are the "name", "displayed-name" and "data". See
<a href="A-new-tree-node.html#A%20new%20tree-node">A new tree-node</a> for a detailed explanation.
<p>The difference between a natural tree like a fir and a tree-buffer is
that the root(-node) of a tree-buffer is not visible but only its
children. In the example below the nodes parent-node-1 and
parent-node-2 are the children of the invisible root-node. Each
tree-buffer has exactly one root-node which is created automatically
by `tree-buffer-create'.
<p>If a tree-node contains at least one child it is displayed with a
special expand/collapse-symbol (see the example below). This symbol
allows expanding (rsp. collapsing) the tree-node wheras expanding
means to display the children-nodes and collapsing means to hide the
childrens of a tree-node.
<p>Here is an example of a tree-buffer:
<br><pre><root-node> ------------------------[root-node (invisible)]
[+] <parent-node-1> -------.
[-] <parent-node-2> -------|
[-] <expanded> --------|
<leaf-node-1> -----|
<leaf-node-2> -----|-----[tree-nodes]
<leaf-node-3> -----|
<leaf-node-4> -----|
[+] <collapsed> -------
|
`-----------------[expand/collapse-symbol]
</pre>
<p>In most cases an action is triggered when clicking with the mouse onto
a tree-node<a rel=footnote href="#fn-1"><sup>1</sup></a> (e.g. clicking onto
"leaf-node-1" or "parent-node-1" in the example above). Which
action is triggered by which key depends on what you specify at
creation-time of the tree-buffer - see <a href="A-new-tree-buffer.html#A%20new%20tree-buffer">A new tree-buffer</a> for
details.
<p>The creation-interface of a tree-buffer allows defining special
popup-menus when clicking with the right mouse-button (of course also
possible via keyboard, see <a href="Tree-buffer-keybindings.html#Tree-buffer%20keybindings">Tree-buffer keybindings</a>) onto a
tree-node (e.g. some senseful actions possible for directory-nodes
like grepping this directory or performing version-control actions for
this directory or something else).
<h5>General recipe for a tree-buffer</h5>
<p>The following sequence of tasks is the general recipe for a
tree-buffer beginning from creation and ending with the display.
<ol type=1 start=1>
</p><li>Create the tree-buffer
Creating a new tree-buffer has to be done with
<code>tree-buffer-create</code> for non ECB-tree-buffers and with the macro
<code>defecb-tree-buffer-creator</code> when the tree-buffer should be used
as an ECB-tree-buffer, so it is an ECB-interactor. See <a href="A-new-tree-buffer.html#A%20new%20tree-buffer">A new tree-buffer</a> for all details.
<li>Add tree-nodes to the tree-buffer
Adding nodes to the new tree-buffer (means make the new tree-buffer
the current buffer and call <code>tree-node-new</code> for a new tree-node
(note that a root-node for this tree-buffer has been autom. created by
<code>tree-buffer-create</code>!). The first tree-node you add to a
tree-buffer must have always the root-node (avaliable via
<code>tree-buffer-get-root</code>) as parent-node. The next nodes can have
either one of the fromerly added nodes or the root-node too. All
tree-nodes haveing the root-node as parent will be displayed at the
toplevel of the tree-buffer. See <a href="A-new-tree-node.html#A%20new%20tree-node">A new tree-node</a> for all
details.
<li>Display the tree-buffer with current nodes and state
When you are finished building up the tree-node-structure call
<code>tree-buffer-update</code> to display the current tree-structure (again
after making the tree-buffer the current-buffer). See <a href="Updating-a-tree-buffer.html#Updating%20a%20tree-buffer">Updating a tree-buffer</a> for all details.
</ol>
<p><strong>IMPORTANT</strong>: First a call of <code>tree-buffer-update</code> updates
the <strong>display</strong> of a tree-buffer, means shows all the tree-nodes
in an emacs-buffer! Neither creating a tree-buffer nor adding
tree-nodes display anything; this just builds the internal
tree-structure.
<p><strong>IMPORTANT</strong>: See <a href="Programming-special-windows.html#Programming%20special%20windows">Programming special windows</a> for details
about programming interactors (special windows) regardless if they
were build as tree or not. There you can find a.o. how to
automatically synchronizing a special window with the current
edit-buffer.
<hr><h4>Footnotes</h4>
<ol type="1">
<li><a name="fn-1"></a>
<p>Of course using the keyboard is also possible,
see <a href="Tree-buffer-keybindings.html#Tree-buffer%20keybindings">Tree-buffer keybindings</a>.</p>
</ol><hr>
</body></html>
|
