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Diffstat (limited to 'lib/gs/src/gs_packer.erl')
| -rw-r--r-- | lib/gs/src/gs_packer.erl | 276 |
1 files changed, 0 insertions, 276 deletions
diff --git a/lib/gs/src/gs_packer.erl b/lib/gs/src/gs_packer.erl deleted file mode 100644 index d16849e4e9..0000000000 --- a/lib/gs/src/gs_packer.erl +++ /dev/null @@ -1,276 +0,0 @@ -%% -%% %CopyrightBegin% -%% -%% Copyright Ericsson AB 1997-2016. All Rights Reserved. -%% -%% Licensed under the Apache License, Version 2.0 (the "License"); -%% you may not use this file except in compliance with the License. -%% You may obtain a copy of the License at -%% -%% http://www.apache.org/licenses/LICENSE-2.0 -%% -%% Unless required by applicable law or agreed to in writing, software -%% distributed under the License is distributed on an "AS IS" BASIS, -%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -%% See the License for the specific language governing permissions and -%% limitations under the License. -%% -%% %CopyrightEnd% -%% - -%% -%% ------------------------------------------------------------ -%% Erlang Graphics Interface geometry manager caclulator -%% ------------------------------------------------------------ - - --module(gs_packer). - --export([pack/2]). -%-compile(export_all). - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -%%%% -%%%% This is a simple packer that take a specification in the format -%%%% -%%%% Spec -> [WidthSpec, WidthSpec....] -%%%% WidthSpec -> {fixed,Size} | {stretch,Weight} | -%%%% {stretch,Weight,Min} | {stretch,Weight,Min,Max} -%%%% -%%%% and a given total size it produces a list of sizes of the -%%%% individual elements. Simple heuristics are used to make the code -%%%% fast and simple. -%%%% -%%%% The Weight is simply a number that is the relative size to the -%%%% other elements that has weights. If for example the weights -%%%% for a frame that has three columns are 40 20 100 it means that -%%%% column 1 has 40/160'th of the space, column 2 20/160'th of -%%%% the space and column 3 100/160'th of the space. -%%%% -%%%% The program try to solve the equation with the constraints given. -%%%% We have tree cases -%%%% -%%%% o We can fullfil the request in the space given -%%%% o We have less space than needed -%%%% o We have more space than allowed -%%%% -%%%% The algorithm is as follows: -%%%% -%%%% 1. Subtract the fixed size, nothing to do about that. -%%%% -%%%% 2. Calculate the Unit (or whatever it should be called), the -%%%% given space minus the fixed sise divided by the Weights. -%%%% -%%%% 3. If we in total can fullfill the request we try to -%%%% fullfill the individual constraints. See remove_failure/2. -%%%% -%%%% 4. If we have too little or too much pixels we take our -%%%% specification and create a new more relaxed one. See -%%%% cnvt_to_min/1 and cnvt_to_max/1. -%%%% -%%%% In general we adjust the specification and redo the whole process -%%%% until we have a specification that meet the total constraints -%%%% and individual constraints. When we know that the constraints -%%%% are satisfied we finally call distribute_space/2 to set the -%%%% resulting size values for the individual elements. -%%%% -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - - -pack(Size, SpecSizes) when Size < 0 -> - pack(0, SpecSizes); -pack(Size, SpecSizes) -> - {Weights,_Stretched,Fixed,Min,Max} = get_size_info(SpecSizes), - Left = Size - Fixed, - Unit = if Weights == 0 -> 0; true -> Left / Weights end, - if - Left < Min -> - NewSpecs = cnvt_to_min(SpecSizes), - pack(Size,NewSpecs); - is_integer(Max), Max =/= 0, Left > Max -> - NewSpecs = cnvt_to_max(SpecSizes), - pack(Size,NewSpecs); - true -> - case remove_failure(SpecSizes, Unit) of - {no,NewSpecs} -> - distribute_space(NewSpecs,Unit); - {yes,NewSpecs} -> - pack(Size, NewSpecs) - end - end. - - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -%%%% -%%%% remove_failure(Specs, Unit) -%%%% -%%%% We know that we in total have enough space to fit within the total -%%%% maximum and minimum requirements. But we have to take care of -%%%% individual minimum and maximum requirements. -%%%% -%%%% This is done with a simple heuristic. We pick the element that -%%%% has the largest diff from the required min or max, change this -%%%% {stretch,W,Mi,Ma} to a {fixed,Mi} or {fixed,Ma} and redo the -%%%% whole process again. -%%%% -%%%% **** BUGS **** -%%%% No known. But try to understand this function and you get a medal ;-) -%%%% -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - - -remove_failure(Specs, Unit) -> - case remove_failure(Specs, Unit, 0) of - {done,NewSpecs} -> - {yes,NewSpecs}; - {_,_NewSpecs} -> - {no,Specs} % NewSpecs == Specs but - end. % we choose the old one - -remove_failure([], _Unit, MaxFailure) -> - {MaxFailure,[]}; -remove_failure([{stretch,W,Mi} | Specs], Unit, MaxFailure) -> - {MinMax,NewMaxFailure} = max_failure(MaxFailure, Mi-W*Unit, 0), - case {MinMax,remove_failure(Specs, Unit, NewMaxFailure)} of - {min,{NewMaxFailure,Rest}} -> - {done,[{fixed,Mi} | Rest]}; - {_,{OtherMaxFailure, Rest}} -> - {OtherMaxFailure,[{stretch,W,Mi} | Rest]} - end; -remove_failure([{stretch,W,Mi,Ma} | Specs], Unit, MaxFailure) -> - {MinMax,NewMaxFailure} = max_failure(MaxFailure, Mi-W*Unit, W*Unit-Ma), - case {MinMax,remove_failure(Specs, Unit, NewMaxFailure)} of - {min,{NewMaxFailure,Rest}} -> - {done,[{fixed,Mi} | Rest]}; - {max,{NewMaxFailure,Rest}} -> - {done,[{fixed,Ma} | Rest]}; - {_,{OtherMaxFailure, Rest}} -> - {OtherMaxFailure,[{stretch,W,Mi,Ma} | Rest]} - end; -remove_failure([Spec | Specs], Unit, MaxFailure) -> - {NewMaxFailure,NewSpecs} = remove_failure(Specs, Unit, MaxFailure), - {NewMaxFailure, [Spec | NewSpecs]}. - -max_failure(LastDiff, DMi, DMa) - when DMi > LastDiff, DMi > DMa -> - {min,DMi}; -max_failure(LastDiff, _DMi, DMa) - when DMa > LastDiff -> - {max,DMa}; -max_failure(MaxFailure, _DMi, _DMa) -> - {other,MaxFailure}. - - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -%%%% -%%%% distribute_space(Spec,Unit) -%%%% -%%%% We now know that we can distribute the space to the elements in -%%%% the list. -%%%% -%%%% **** BUGS **** -%%%% No known bugs. It try hard to distribute the pixels so that -%%%% there should eb no pixels left when done but there is no proof -%%%% that this is the case. The distribution of pixels may also -%%%% not be optimal. The rounding error from giving one element some -%%%% pixels is added to the next even if it would be better to add -%%%% it to an element later in the list (for example the weights -%%%% 1000, 2, 1000). But this should be good enough. -%%%% -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - - -distribute_space(Specs, Unit) -> - distribute_space(Specs, Unit, 0.0). - -distribute_space([], _Unit, _Err) -> - []; -distribute_space([Spec | Specs], Unit, Err) -> - distribute_space(Spec, Specs, Unit, Err). - -distribute_space({fixed,P}, Specs, Unit, Err) -> - [P | distribute_space(Specs, Unit, Err)]; -distribute_space({stretch,Weight}, Specs, Unit, Err) -> - Size = Weight * Unit + Err, - Pixels = round(Size), - NewErr = Size - Pixels, - [Pixels | distribute_space(Specs, Unit, NewErr)]; -distribute_space({stretch,W,_Mi}, Specs, Unit, Err) -> - distribute_space({stretch,W}, Specs, Unit, Err); -distribute_space({stretch,W,_Mi,_Ma}, Specs, Unit, Err) -> - distribute_space({stretch,W}, Specs, Unit, Err). - - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -%%%% -%%%% cnvt_to_min(Spec) -%%%% cnvt_to_max(Spec) -%%%% -%%%% If the space we got isn't enough for the total minimal or maximal -%%%% requirements then we convert the specification to a more relaxed -%%%% one that we always can satisfy. -%%%% -%%%% This is fun! We do a simple transformation from one specification -%%%% to a new one. The min, max and fixed size are our new weights! -%%%% This way the step from a specification we can satisfy and one -%%%% close that we can't is only a few pixels away, i.e. the transition -%%%% from within the constraints and outside will be smooth. -%%%% -%%%% **** BUGS **** -%%%% No known bugs. -%%%% -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - - -cnvt_to_min([]) -> - []; -cnvt_to_min([Spec | Specs]) -> - cnvt_to_min(Spec, Specs). - -cnvt_to_max([]) -> - []; -cnvt_to_max([Spec | Specs]) -> - cnvt_to_max(Spec, Specs). - -cnvt_to_min({fixed,P}, Specs) -> - [{stretch,P} | cnvt_to_min(Specs)]; -cnvt_to_min({stretch,_W}, Specs) -> - [{fixed,0} | cnvt_to_min(Specs)]; -cnvt_to_min({stretch,_W,Mi}, Specs) -> - [{stretch,Mi} | cnvt_to_min(Specs)]; -cnvt_to_min({stretch,_W,Mi,_Ma}, Specs) -> - [{stretch,Mi} | cnvt_to_min(Specs)]. - -%% We know that there can only be {fixed,P} and {stretch,W,Mi,Ma} -%% in this list. - -cnvt_to_max({fixed,P}, Specs) -> - [{stretch,P} | cnvt_to_max(Specs)]; -cnvt_to_max({stretch,_W,_Mi,Ma}, Specs) -> - [{stretch,Ma} | cnvt_to_max(Specs)]. - - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -%%%% -%%%% Sum the Weights, Min and Max etc -%%%% -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -get_size_info(Specs) -> - get_size_info(Specs, 0, 0, 0, 0, 0). - -get_size_info([], TotW, NumW, TotFixed, TotMin, TotMax) -> - {TotW, NumW, TotFixed, TotMin, TotMax}; -get_size_info([Spec | Specs], TotW, NumW, TotFixed, TotMin, TotMax) -> - get_size_info(Spec, TotW, NumW, TotFixed, TotMin, TotMax, Specs). - -get_size_info({fixed,P}, TotW, NumW, TotFixed, TotMin, TotMax, Specs) -> - get_size_info(Specs, TotW, NumW, TotFixed+P, TotMin, TotMax); -get_size_info({stretch,W}, TotW, NumW, TotFixed, TotMin, _TotMax, Specs) -> - get_size_info(Specs, TotW+W, NumW+1, TotFixed, TotMin, infinity); -get_size_info({stretch,W,Mi}, TotW, NumW, TotFixed, TotMin, _TotMax, Specs) -> - get_size_info(Specs, TotW+W, NumW+1, TotFixed, TotMin+Mi, infinity); -get_size_info({stretch,W,Mi,_Ma}, TotW, NumW, TotFixed, TotMin, infinity, Specs) -> - get_size_info(Specs, TotW+W, NumW+1, TotFixed, TotMin+Mi, infinity); -get_size_info({stretch,W,Mi,Ma}, TotW, NumW, TotFixed, TotMin, TotMax, Specs) -> - get_size_info(Specs, TotW+W, NumW+1, TotFixed, TotMin+Mi, TotMax+Ma). |