src/kits/interface/layouter/CollapsingLayouter.h

   1 /*
   2  * Copyright 2011, Haiku, Inc.
   3  * All rights reserved. Distributed under the terms of the MIT License.
   4  */
   5 #ifndef COLLAPSING_LAYOUTER_H
   6 #define COLLAPSING_LAYOUTER_H
   7
   8 #include "Layouter.h"
   9
  10
  11 namespace BPrivate {
  12 namespace Layout {
  13
  14
  15 /* This layouter wraps either a Compound, Simple or OneElement layouter, and
  16  * removes elements which have no constraints, or min/max constraints of
  17  * B_SIZE_UNSET. The child layouter is given only the constraints for the
  18  * remaining elements. When using the LayoutInfo of this layouter,
  19  * collapsed (removed) elements are given no space on screen.
  20  */
  21 class CollapsingLayouter : public Layouter {
  22 public:
  23                                                                 CollapsingLayouter(int32 elementCount,
  24                                                                         float spacing);
  25         virtual                                         ~CollapsingLayouter();
  26
  27         virtual void                            AddConstraints(int32 element, int32 length,
  28                                                                         float min, float max, float preferred);
  29         virtual void                            SetWeight(int32 element, float weight);
  30
  31         virtual float                           MinSize();
  32         virtual float                           MaxSize();
  33         virtual float                           PreferredSize();
  34
  35         virtual LayoutInfo*                     CreateLayoutInfo();
  36
  37         virtual void                            Layout(LayoutInfo* layoutInfo, float size);
  38
  39         virtual Layouter*                       CloneLayouter();
  40
  41
  42 private:
  43         class   ProxyLayoutInfo;
  44         struct  Constraint;
  45         struct  ElementInfo;
  46
  47                         void                            _ValidateLayouter();
  48                         Layouter*                       _CreateLayouter();
  49                         void                            _DoCollapse();
  50                         void                            _AddConstraints();
  51                         void                            _AddConstraints(int32 position,
  52                                                                         const Constraint* c);
  53                         void                            _SetWeights();
  54
  55                         int32                           fElementCount;
  56                         ElementInfo*            fElements;
  57                         int32                           fValidElementCount;
  58                         bool                            fHaveMultiElementConstraints;
  59                         float                           fSpacing;
  60                         Layouter*                       fLayouter;
  61 };
  62
  63 } // namespace Layout
  64 } // namespace BPrivate
  65
  66 using BPrivate::Layout::CollapsingLayouter;
  67
  68 #endif // COLLAPSING_LAYOUTER_H