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
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
|
%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1996-2009. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%%
%% %CopyrightEnd%
%%
-module(canvasbutton).
-compile([{nowarn_deprecated_function,{gs,config,2}},
{nowarn_deprecated_function,{gs,create,3}},
{nowarn_deprecated_function,{gs,read,2}}]).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% Erlang Toolbar
%
%%% Description %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% Extension to GS used to imitate buttons but instead using images drawn
% on a canvas. Enables usage of .gif files as button images and not only
% .xbm (bitmap) files.
%
%%% Constants %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
-define(gray,{87,87,87}).
%
%%% Internal data structures %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% canvasbutton()
-record(canvasbutton,{image,rect,ul,ll}).
%
% cboptions()
-record(cboptions,
{imagefile=nofile, % nofile |
% string() Name of image file
x=0, % integer() X coordinate relative the canvas
y=0, % integer() Y coordinate relative the canvas
width=10, % integer() Button width
height=10, % integer() Button heigth
fg=black, % atom() Foreground color
data=[]}). % term() Data associated with button events
%
%%% Exports %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
-export([create/1,create/2,read/2,press/1,release/1]).
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%% Exported functions %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%----------------------------------------
% create(Canvas) => create(Canvas,[])
% create(Canvas,OptionList) => canvasbutton()
% Canvas - GS canvas object
% OptionList - [{Option,Value}]
% Option, Value - see below
% Create a canvasbutton with the given image on Canvas
%
% Option Value Default Comment
% ----------------------------------------------------------------
% image nofile | nofile Name of image file. Must be a bitmap
% string() file (.xbm) or a GIF file (.gif).
% x integer() 0 X coordinate relative to Canvas
% y integer() 0 Y coordinate relative to Canvas
% width integer() 10 Button width
% height integer() 10 Button height
% fg atom() black Foreground color, bitmaps only
% data term() [] Data associated with button events
%
% The process calling this function will receive the following events:
% {gs,GsObj,enter,{canvasbutton,Canvasbutton,Data},Args}
% {gs,GsObj,leave,{canvasbutton,Canvasbutton,Data},Args}
% {gs,GsObj,buttonpress,{canvasbutton,Canvasbutton,Data},Args}
% {gs,GsObj,buttonrelease,{canvasbutton,Canvasbutton,Data},Args}
% where GsObj and Args are a GS object and its Args field, respectively.
%
% Note that press/1 and release/1 has to be called explicitly to create
% the illusion of the button being pressed or released.
%----------------------------------------
create(Canvas) ->
create(Canvas,[]).
create(Canvas,OptionList) ->
Options = sort_out_options(OptionList),
X = Options#cboptions.x,
Y = Options#cboptions.y,
W = Options#cboptions.width,
H = Options#cboptions.height,
%% Buttons should have the same background color as the canvas
Bg = gs:read(Canvas,bc),
%% Draw image
Image = create_image(Options#cboptions.imagefile,Canvas,Bg,
Options#cboptions.fg,X,Y,W,H),
%% Draw upper left corner line
Ul = gs:create(line,Canvas,[{coords,[{X,Y+H},{X,Y},{X+W,Y}]},
{fg,white},{width,2}]),
%% Draw lower right corner line
Ll = gs:create(line,Canvas,[{coords,[{X,Y+H},{X+W,Y+H},{X+W,Y}]},
{fg,?gray},{width,2}]),
%% Draw a rectangle around all (for event catching when width and
%% height of button is larger than image)
Rect = gs:create(rectangle,Canvas,[{coords,[{X,Y},{X+W,Y+H}]},
{fill,Bg},
{buttonpress,true},
{buttonrelease,true},
{enter,true},{leave,true}]),
%% Now the canvas button is created
Canvasbutton = #canvasbutton{image=Image,rect=Rect,ul=Ul,ll=Ll},
Data = Options#cboptions.data,
gs:config(Rect,{data,{canvasbutton,Canvasbutton,Data}}),
gs:config(Image,{data,{canvasbutton,Canvasbutton,Data}}),
gs:config(Rect,lower),
gs:config(Image,raise),
Canvasbutton.
%----------------------------------------
% read(Canvasbutton,coords) => [{L,T},{R,B}]
% Canvasbutton - canvasbutton()
% Read a Canvasbutton's coordinates
%----------------------------------------
read(Canvasbutton,coords) ->
gs:read(Canvasbutton#canvasbutton.rect,coords).
%----------------------------------------
% press(Canvasbutton)
% Canvasbutton - canvasbutton()
% Create the illusion that Canvasbutton is pressed
%----------------------------------------
press(Canvasbutton) ->
gs:config(Canvasbutton#canvasbutton.ul,{fg,?gray}),
gs:config(Canvasbutton#canvasbutton.ll,{fg,white}),
case Canvasbutton#canvasbutton.image of
noimage ->
ignore;
Image ->
gs:config(Image,{move,{-1,-1}})
end.
%----------------------------------------
% release(Canvasbutton)
% Canvasbutton - canvasbutton()
% Create the illusion that Canvasbutton is released
%----------------------------------------
release(Canvasbutton) ->
gs:config(Canvasbutton#canvasbutton.ul,{fg,white}),
gs:config(Canvasbutton#canvasbutton.ll,{fg,?gray}),
case Canvasbutton#canvasbutton.image of
noimage ->
ignore;
Image ->
gs:config(Image,{move,{1,1}})
end.
%%% Internal functions %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%----------------------------------------
% create_image(ImageFile,Canvas,Bg,Fg,X,Y,W,H) => Image
% ImageFile - string() Image file, must exist and be a bitmap file ending
% with .xbm or a GIF file ending with .gif.
% Canvas - GS canvas object
% Bg - atom() Background color (bitmaps only)
% Fg - atom() Foreground color (bitmaps only)
% X, Y - int() X and Y coordinates for Image relative to Canvas
% W, H - int() Width and height of Image
% Image - GS canvas image object
%----------------------------------------
create_image(nofile,_,_,_,_,_,_,_) ->
noimage;
create_image(ImageFile,Canvas,Bg,Fg,X,Y,W,H) ->
case lists:last(string:tokens(ImageFile,".")) of
"xbm" ->
gs:create(image,Canvas,
[{bitmap,ImageFile},
{bg,Bg},{fg,Fg},
{anchor,c},
{coords,[{X+1+W/2,Y+1+H/2}]},
{buttonpress,true},
{buttonrelease,true},
{enter,true},{leave,true}]);
"gif" ->
gs:create(image,Canvas,
[{load_gif,ImageFile},
{anchor,c},
{coords,[{X+W/2,Y+H/2}]},
{buttonpress,true},
{buttonrelease,true},
{enter,true},{leave,true}])
end.
%----------------------------------------
% sort_out_options(OptionList) => cboptions()
% OptionList - see create/2
% Insert members of option list into a cboptions record.
%----------------------------------------
sort_out_options(OptionList) ->
sort_out_options(OptionList,#cboptions{}).
%----------------------------------------
% sort_out_options(OptionList,Options) => cboptions()
% OptionList - see create/2
% Options - cboptions()
% Called by sort_out_options/1.
%----------------------------------------
sort_out_options([{image,Image}|Rest],Options) ->
sort_out_options(Rest,Options#cboptions{imagefile=Image});
sort_out_options([{x,X}|Rest],Options) ->
sort_out_options(Rest,Options#cboptions{x=X});
sort_out_options([{y,Y}|Rest],Options) ->
sort_out_options(Rest,Options#cboptions{y=Y});
sort_out_options([{width,Width}|Rest],Options) ->
sort_out_options(Rest,Options#cboptions{width=Width});
sort_out_options([{height,Height}|Rest],Options) ->
sort_out_options(Rest,Options#cboptions{height=Height});
sort_out_options([{fg,Fg}|Rest],Options) ->
sort_out_options(Rest,Options#cboptions{fg=Fg});
sort_out_options([{data,Data}|Rest],Options) ->
sort_out_options(Rest,Options#cboptions{data=Data});
sort_out_options([],Options) ->
Options.
|
