%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1996-2012. 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.
