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
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
|
$Id: Files.txt,v 1.3 2004/12/24 01:54:03 hobbs Exp $
This document describes the operating system independent file handling
capability in Tix. This is pertinent up to Tix 8.2, but isn't 100%
correct for Tix 8.4, where the FS handling was simplified using more
Tcl core file routines. In general, this should all no longer be
relevant for Tix 8.4 users. Use Tcl core routines instead.
1. The problem:
(A) Handling user inputs. In various Tix widgets, the user may enter
a text string to refer to a file, a directory or a file pattern.
File:
tixFileEntry
tixFileSelectBox, the Selection part
Directory:
tixDirBox
tixExFileSelectBox, the "Directory" part
Pattern:
tixFileSelectBox, the "Pattern" part
tixExFileSelectBox, the "File" part
(B) Interfacing with application
These widgets support a -directory option
tixDirList
tixDirTree
tixFileSelectBox
tixExFileSelectBox
These widgets support a -pattern option
tixFileSelectBox
tixExFileSelectBox
(C) Displaying the file system in a single hierarchy
tixDirList
tixDirTree
2. Issues:
(A) Unix:
Tilde expansion
(B) Windows:
No single file system hierarchy.
(C) Both:
Need to translate relative pathnames, "." and ".."
3. Reusuability:
Many widgets need to list directory, glob, display hierarchy. We
don't want to rewrite the same code again and again.
4. API.
(A) Types of API
External interface: Takes an input from the user or from the
application and translate it to a canonical form.
Internal interface: operate on filenames that are in canonical
forms. There are run-time checking whether the filenames arein
canonical forms.
We have the two types of interfaces so that we don't need to
perform needless translations from "user form" to "canonical
form".
(B) API Consistency
External API always takes a filename in the native format and
return file names in the native format.
(C) Errors
User errors are reported in an error dialog. Application errors
triggers a TCL error return code.
There should be in-line comments stating whether an input is from
user or application.
5. VPATH: virtual hierarchical path
Unix:
In Unix, a VPATH is the same as a file pathname.
Windows:
In Windows 3.1, a VPATH is "xx\" followed by a normalized DOS
file pathname. "xx" by itself is "My computer" and refers to the
root directory of the C: drive.
In Windows 95, a VPATH is "xx\xx\" followed by a normalized DOS
file pathname. "xx" by itself is "Desktop" and refers to
"C:\Windows\Desktop". "xx\xx" by itself is "My computer" and
refers to the root directory of the C: drive.
Normalization do not go into the virtual prefix. E.g.: the VPATH for
"C:\Windows\..\..\" is "xx\xx\C:", not "xx\xx".
6. Normalization:
tixFSNorm context text defFile flagsVar errorMsgVar
This is the main function that translate a user input to
normalized (canonical) form.
Parameters:
context:VPATH
The "current directory" under which the translation
occurs. It is used only if text refers to a relative
pathname.
if context is the empty string, then text must refer to an
absolute path.
text:string
The (user/application) input that needs to be
normalized. The exact mode of translation depends on the
flags
defFile:string
If the input is a directory, append this to the directory.
flagsVar: ref to array
flag(noPattern): we don't want patterns. Treat all wild
card characters as normal file names
Return value:
No error occurs: errorMsg is not set and a list of three
elements is returned:
index 0: the normalized path of the input
index 1: the VPATH of the directory.
index 2: file(s) in the directory.
index 3: pattern(s) in the directory.
Either index 1 or 2, or both, are empty strings. They cannot
be both non-empty.
A Normalized path:
1) is absolute
2) has no double slashes
3) has no trailing slashes
4) has no relative pathnames
5) has no tildes
file normalize directory
This is mainly used to check the validity of -directory option
of the widgets.
Parameter:
directory:
Must be an existing absolute path.
Return value:
Returns normalized path. Error given when directory is not an
existing absolute path
7. VPATH translation:
tixFSVPath pathname: returns the VPATH of pathname
tixFSPath VPATH: returns the pathname of VPATH
8. Valid file names:
Should prompt to user about invalid filenames (E.g. In Windows,
names cannot contain "*")
9. Creation prompt:
If user enters a file or directory that doesn't exist, promt to ask
whether he wants to create it.
10.
|
