/* -*-objc-*-
   GSAutoLayoutGrid.m

   Copyright (C) 2008 Free Software Foundation, Inc.

   Author: Nicola Pero <nicola.pero@meta-innovation.com>
   Date: March 2008

   This file is part of GNUstep Renaissance

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.
   
   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with this library; see the file COPYING.LIB.
   If not, write to the Free Software Foundation,
   59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <AutoLayoutCommonInclude.h>

#include "GSAutoLayoutGrid.h"
#include "GSAutoLayoutManager.h"
#include "GSAutoLayoutStandardManager.h"
#include "GSAutoLayoutProportionalManager.h"
#include "GSAutoLayoutDefaults.h"

/* This is basically a struct which can be stored into a NSArray - all
 * ivars (except setting _view, which is set when the info is created
 * and destroyed when the info is destroyed) accessed directly.  */
@interface GSAutoLayoutGridViewInfo : NSObject
{
@public
  NSView *_view;

  /* The view minimum size.  When the view is first added, its size
   * is automatically used as the view minimum size.  You can change
   * the minimum size later on programmatically by specifying a new
   * minimum size, or by asking the autolayout view to update
   * itself, in which case the autolayout view examines all views,
   * and if any view has a size which is different from the size it
   * is supposed to have, the new size is used as the view's minimum
   * size.  */
  NSSize _minimumSize;

  /* Expand/Alignment in the horizontal direction.  */
  GSAutoLayoutAlignment _hAlignment;

  /* Expands/Alignment in the vertical direction.  */
  GSAutoLayoutAlignment _vAlignment;
    
  /* A horizontal border.  */
  float _hBorder;
  
  /* A vertical border.  */
  float _vBorder;

  /* The position of the view in the grid.  */
  int _rowPosition;
  int _columnPosition;

  /* For views spanning multiple columns or rows.  */
  int _columnSpan;
  int _rowSpan;
}
- (id) initWithView: (NSView *)view;
@end

@implementation GSAutoLayoutGridViewInfo
- (id) initWithView: (NSView *)view
{
  ASSIGN (_view, view);
  return self;
}

- (void) dealloc
{
  RELEASE (_view);
  [super dealloc];
}
@end

@implementation GSAutoLayoutGrid
- (id) init
{
  GSAutoLayoutManager *manager;

  self = [super initWithFrame: NSZeroRect];
  /* Turn off traditional OpenStep subview autoresizing.  */
  [self setAutoresizesSubviews: NO];
  /* By default we are resizable in width and height ... in case we
   * are placed top-level in the window: we want to receive all
   * resizing of the window around us.  */
  [self setAutoresizingMask: NSViewWidthSizable | NSViewHeightSizable];

  _viewInfo = [NSMutableArray new];

  /* The column layout manager is by default a standard one, but could
   * be changed.  */
  manager = [GSAutoLayoutStandardManager new];
  [self setColumnAutoLayoutManager: manager];
  RELEASE (manager);

  /* The row layout manager is by default a standard one, but could be
   * changed.  */
  manager = [GSAutoLayoutStandardManager new];
  [self setRowAutoLayoutManager: manager];
  RELEASE (manager);

  return self;
}

- (void) dealloc
{
  RELEASE (_rowManager);
  RELEASE (_columnManager);
  RELEASE (_viewInfo);
  RELEASE (_rows);
  RELEASE (_columns);
  [super dealloc];
}

- (void) setRowGridType: (GSAutoLayoutBoxType)type
{
  if (type != [self rowGridType])
    {
      GSAutoLayoutManager *manager = nil;

      if (type == GSAutoLayoutProportionalBox)
	{
	  manager = [GSAutoLayoutProportionalManager new];
	}
      else
	{
	  manager = [GSAutoLayoutStandardManager new];
	}

      [self setRowAutoLayoutManager: manager];
      RELEASE (manager);
    }
}

- (GSAutoLayoutBoxType) rowGridType
{
  if ([_rowManager isKindOfClass: [GSAutoLayoutProportionalManager class]])
    {
      return GSAutoLayoutProportionalBox;
    }
  else
    {
      return GSAutoLayoutStandardBox;
    }
}

- (void) setColumnGridType: (GSAutoLayoutBoxType)type
{
  if (type != [self columnGridType])
    {
      GSAutoLayoutManager *manager = nil;

      if (type == GSAutoLayoutProportionalBox)
	{
	  manager = [GSAutoLayoutProportionalManager new];
	}
      else
	{
	  manager = [GSAutoLayoutStandardManager new];
	}

      [self setColumnAutoLayoutManager: manager];
      RELEASE (manager);
    }
}

- (GSAutoLayoutBoxType) columnGridType
{
  if ([_columnManager isKindOfClass: [GSAutoLayoutProportionalManager class]])
    {
      return GSAutoLayoutProportionalBox;
    }
  else
    {
      return GSAutoLayoutStandardBox;
    }
}

- (void) setRowAutoLayoutManager: (GSAutoLayoutManager *)aLayoutManager
{
  /* NB: this method currently only works if you call it when there
   * are no views in the grid.  TODO: Extend it.
   */
  ASSIGN (_rowManager, aLayoutManager);

  ASSIGN (_columns, [NSMutableArray new]);
  RELEASE (_columns);
  
  [[NSNotificationCenter defaultCenter] 
    addObserver: self
    selector: @selector(rowAutoLayoutManagerChangedLayout:)
    name: GSAutoLayoutManagerChangedLayoutNotification
    object: _rowManager];
}

- (GSAutoLayoutManager *)rowAutoLayoutManager
{
  return _rowManager;
}

- (void) setColumnAutoLayoutManager: (GSAutoLayoutManager *)aLayoutManager
{
  /* NB: this method currently only works if you call it when there
   * are no views in the grid.  TODO: Extend it.
   */
  ASSIGN (_columnManager, aLayoutManager);

  ASSIGN (_rows, [NSMutableArray new]);
  RELEASE (_rows);
  
  [[NSNotificationCenter defaultCenter] 
    addObserver: self
    selector: @selector(columnAutoLayoutManagerChangedLayout:)
    name: GSAutoLayoutManagerChangedLayoutNotification
    object: _columnManager];
}

- (GSAutoLayoutManager *)columnAutoLayoutManager
{
  return _columnManager;
}

- (void) addRow
{
  id newLine = [_columnManager addLine];

  {
    int i, count = [_columns count];
    for (i = 0; i < count; i++)
      {
	[_columnManager insertNewSegmentAtIndex: 0
		     inLine: newLine];
      }
  }

  [_rows addObject: newLine];

  /* Now we have a new row.  Add an empty segment at the end of every
   * column.  */
  {
    int i, count = [_columns count];
    for (i = 0; i < count; i++)
      {
	id line = [_columns objectAtIndex: i];
	[_rowManager insertNewSegmentAtIndex: 
		       [_rowManager segmentCountInLine: line]
		     inLine: line];
      }
  }

  /* Finally, just in case this is the first row we add, we make sure
   * we force the size of the row to be our frame size.  */
  [_columnManager forceLength: ([self frame]).size.width 
		  ofLine: [_rows objectAtIndex: 0]];
}

- (void) removeRow
{
  [_columnManager removeLine: [_rows lastObject]];
  [_rows removeLastObject];
  /* TODO: Remove all segments for that row in all lines of the row manager.  */
  /* TODO: Remove all views that were in that row.  */
}

- (NSUInteger) numberOfRows
{
  return [_rows count];
}

- (void) addColumn
{
  id newLine = [_rowManager addLine];

  {
    int i, count = [_rows count];
    for (i = 0; i < count; i++)
      {
	[_rowManager insertNewSegmentAtIndex: 0
		     inLine: newLine];
      }
  }

  [_columns addObject: newLine];

  /* Now we have a new column.  Add an empty segment at the end of
   * every row.  */
  {
    int i, count = [_rows count];
    for (i = 0; i < count; i++)
      {
	id line = [_rows objectAtIndex: i];
	[_columnManager insertNewSegmentAtIndex: 
			  [_columnManager segmentCountInLine: line]
			inLine: line];
      }
  }

  /* Finally, just in case this is the first column we add, we make
   * sure we force the size of the column to be our frame size.  */
  [_rowManager forceLength: ([self frame]).size.height
		  ofLine: [_columns objectAtIndex: 0]];
}

- (void) removeColumn
{
  [_rowManager removeLine: [_columns lastObject]];
  [_columns removeLastObject];
  /* TODO: Remove all segments for that column in all lines of the column manager.  */
  /* TODO: Remove all views that were in that column.  */
}

- (NSUInteger) numberOfColumns
{
  return [_columns count];
}

/* Private method to retrieve the info for a view.  */
- (GSAutoLayoutGridViewInfo *) infoForView: (NSView *)aView
{
  int i, count = [_viewInfo count];
  
  for (i = 0; i < count; i++)
    {
      GSAutoLayoutGridViewInfo *info = [_viewInfo objectAtIndex: i];
      
      if (info->_view == aView)
	{
	  return info;
	}
    }
  return nil;
}

/* Private methods to push layout info to layout managers.  */
- (void) pushViewInfoToAutoLayoutManagers: (GSAutoLayoutGridViewInfo *)info
{
  /* TODO: Support span properly!  We need to set the view information
   * in multiple lines.
   */
  /* FIXME: Support span properly!  The info->_columnPosition is not
   * necessarily the segment index if there are views with span !=
   * 1.  */
  [_columnManager setMinimumLength: (info->_minimumSize).width
		  alignment: info->_hAlignment
		  minBorder: info->_hBorder
		  maxBorder: info->_hBorder
		  span: info->_columnSpan
		  ofSegmentAtIndex: info->_columnPosition
		  inLine: [_rows objectAtIndex: info->_rowPosition]];

  [_rowManager setMinimumLength: (info->_minimumSize).height
	       alignment: info->_vAlignment
	       minBorder: info->_vBorder
	       maxBorder: info->_vBorder
	       span: info->_rowSpan
	       ofSegmentAtIndex: info->_rowPosition
	       inLine: [_columns objectAtIndex: info->_columnPosition]];
}

- (void) addView: (NSView *)aView
	   inRow: (int)row
	  column: (int)column
{
  GSAutoLayoutGridViewInfo *info;

  info = [[GSAutoLayoutGridViewInfo alloc] initWithView: aView];
  info->_minimumSize = [aView frame].size;
  info->_hAlignment = [aView autolayoutDefaultHorizontalAlignment];
  info->_vAlignment = [aView autolayoutDefaultVerticalAlignment];
  info->_hBorder = [aView autolayoutDefaultHorizontalBorder];
  info->_vBorder = [aView autolayoutDefaultVerticalBorder];
  info->_rowPosition = row;
  info->_columnPosition = column;
  info->_rowSpan = 1;
  info->_columnSpan = 1;
  
  if (info->_hAlignment == GSAutoLayoutExpand)
    {
      _hExpand = YES;
    }
  if (info->_hAlignment == GSAutoLayoutWeakExpand)
    {
      _hWeakExpand = YES;
   }

  if (info->_vAlignment == GSAutoLayoutExpand)
    {
      _vExpand = YES;
    }
  if (info->_vAlignment == GSAutoLayoutWeakExpand)
    {
      _vWeakExpand = YES;
    }

  [_viewInfo addObject: info];
  RELEASE (info);
  [self addSubview: aView];

  if (info->_columnSpan != 1)
    {
      /* FIXME - need to work out the segments!  */
    }

  if (info->_rowSpan != 1)
    {
      /* FIXME - need to work out the segments!  */
    }

  [self pushViewInfoToAutoLayoutManagers: info];
}

- (void) removeView: (NSView *)aView
{
  /* TODO */
}

- (int) numberOfViewsInRow: (int)row
{
  /* FIXME: This is incorrect since we add segments for non-existing views.  */
  return [_columnManager segmentCountInLine: [_rows objectAtIndex: row]];
}

- (int) numberOfViewsInColumn: (int)column
{
  /* FIXME: This is incorrect since we add segments for non-existing views.  */
  return [_rowManager segmentCountInLine: [_columns objectAtIndex: column]];
}

/* Internal method which will get all the autolayout information from
 * the autolayout managers, and use it to resize all views.  This is
 * an expensive method and you should be calling it as little as
 * possible.  The method gets information from both the autolayout
 * managers in a single go.  */
- (void) updateViewsWithNewAutoLayout
{
  float newWidth, newHeight;

  newWidth = [_columnManager lineLength];
  newHeight = [_rowManager lineLength];

  [super setFrameSize: NSMakeSize (newWidth, newHeight)];
  
  {
    NSEnumerator *e = [_viewInfo objectEnumerator];
    GSAutoLayoutGridViewInfo *info;

    while ((info = [e nextObject]) != nil)
      {
	NSRect newFrame;
	id column = [_columns objectAtIndex: info->_columnPosition];
	id row = [_rows objectAtIndex: info->_rowPosition];
	GSAutoLayoutSegmentLayout rowSegment, columnSegment;

	rowSegment = [_rowManager layoutOfSegmentAtIndex: info->_rowPosition
				  inLine: column];
	columnSegment = [_columnManager layoutOfSegmentAtIndex: info->_columnPosition
					inLine: row];
	
	newFrame.origin.x = columnSegment.position;
	newFrame.origin.y = rowSegment.position;
	newFrame.size.width = columnSegment.length;
	newFrame.size.height = rowSegment.length;
	
	[info->_view setFrame: newFrame];
      }
  }
}

- (void) updateLayout
{
  _performingLayoutUpdate = YES;

  /* TODO: we should be catching exceptions here, and making sure we
   * always set _performingLayoutUpdate back to NO at the end.  */

  [_rowManager updateLayout];
  [_columnManager updateLayout];

  [self updateViewsWithNewAutoLayout];

  _performingLayoutUpdate = NO;
}

- (void) rowAutoLayoutManagerChangedLayout: (NSNotification *)notification
{
  if (_performingLayoutUpdate)
    {
      return;
    }

  [self updateViewsWithNewAutoLayout];
}

- (void) columnAutoLayoutManagerChangedLayout: (NSNotification *)notification
{
  if (_performingLayoutUpdate)
    {
      return;
    }

  [self updateViewsWithNewAutoLayout];
}

- (int) numberOfViews
{
  return [_viewInfo count];
}

- (void) setFrame: (NSRect)frame
{
  if (NSEqualRects ([self frame], frame))
    {
      return;
    }

  [super setFrame: frame];

  if ([_columns count] > 0)
    {
      [_rowManager forceLength: frame.size.height 
		   ofLine: [_columns objectAtIndex: 0]];
    }
  
  if ([_rows count] > 0)
    {
      [_columnManager forceLength: frame.size.width 
		      ofLine: [_rows objectAtIndex: 0]];
    }

  [self updateLayout];
}

- (void) setFrameSize: (NSSize)size
{
  NSSize oldSize = [self frame].size;
  
  if (oldSize.width == size.width && oldSize.height == size.height)
    {
      return;
    }

  [super setFrameSize: size];

  if ([_columns count] > 0)
    {
      [_rowManager forceLength: size.height 
		   ofLine: [_columns objectAtIndex: 0]];
    }
  
  if ([_rows count] > 0)
    {
      [_columnManager forceLength: size.width 
		      ofLine: [_rows objectAtIndex: 0]];
    }

  [self updateLayout];
}

- (void) setMinimumSize: (NSSize)aSize  forView: (NSView *)aView
{
  GSAutoLayoutGridViewInfo *info = [self infoForView: aView];
  info->_minimumSize = aSize;

  [self pushViewInfoToAutoLayoutManagers: info];
}

- (NSSize) minimumSizeForView: (NSView *)aView
{
  GSAutoLayoutGridViewInfo *info = [self infoForView: aView];
  return info->_minimumSize;
}


- (void) setHorizontalAlignment: (GSAutoLayoutAlignment)flag  
			forView: (NSView *)aView
{
  GSAutoLayoutGridViewInfo *info = [self infoForView: aView];
  info->_hAlignment = flag;

  /* Recompute the _hExpand and _hWeakExpand flags.  */
  {
    NSEnumerator *e = [_viewInfo objectEnumerator];
    GSAutoLayoutGridViewInfo *viewInfo;

    _hExpand = NO;
    _hWeakExpand = NO;

    while ((viewInfo = [e nextObject]) != nil)
      {
	if (viewInfo->_hAlignment == GSAutoLayoutExpand)
	  {
	    _hExpand = YES;
	  }
	if (viewInfo->_hAlignment == GSAutoLayoutWeakExpand)
	  {
	    _hWeakExpand = YES;
	  }
      }
  }

  [self pushViewInfoToAutoLayoutManagers: info];
}

- (GSAutoLayoutAlignment) horizontalAlignmentForView: (NSView *)aView
{
  GSAutoLayoutGridViewInfo *info = [self infoForView: aView];
  return info->_hAlignment;
}


- (void) setVerticalAlignment: (GSAutoLayoutAlignment)flag  
		      forView: (NSView *)aView
{
  GSAutoLayoutGridViewInfo *info = [self infoForView: aView];
  info->_vAlignment = flag;

  /* Recompute the _vExpand and _vWeakExpand flags.  */
  {
    NSEnumerator *e = [_viewInfo objectEnumerator];
    GSAutoLayoutGridViewInfo *viewInfo;

    _vExpand = NO;
    _vWeakExpand = NO;

    while ((viewInfo = [e nextObject]) != nil)
      {
	if (viewInfo->_vAlignment == GSAutoLayoutExpand)
	  {
	    _vExpand = YES;
	  }
	if (viewInfo->_vAlignment == GSAutoLayoutWeakExpand)
	  {
	    _vWeakExpand = YES;
	  }
      }
  }

  [self pushViewInfoToAutoLayoutManagers: info];
}

- (GSAutoLayoutAlignment) verticalAlignmentForView: (NSView *)aView
{
  GSAutoLayoutGridViewInfo *info = [self infoForView: aView];
  return info->_vAlignment;
}

- (void) setHorizontalBorder: (float)border  forView: (NSView *)aView
{
  GSAutoLayoutGridViewInfo *info = [self infoForView: aView];
  info->_hBorder = border;

  [self pushViewInfoToAutoLayoutManagers: info];
} 

- (float) horizontalBorderForView: (NSView *)aView
{
  GSAutoLayoutGridViewInfo *info = [self infoForView: aView];
  return info->_hBorder;
}

- (void) setVerticalBorder: (float)border  forView: (NSView *)aView
{
  GSAutoLayoutGridViewInfo *info = [self infoForView: aView];
  info->_vBorder = border;

  [self pushViewInfoToAutoLayoutManagers: info];
}

- (float) verticalBorderForView: (NSView *)aView
{
  GSAutoLayoutGridViewInfo *info = [self infoForView: aView];
  return info->_vBorder;
}

- (void) setRowSpan: (int)span  
	    forView: (NSView *)aView
{
  GSAutoLayoutGridViewInfo *info = [self infoForView: aView];
  info->_rowSpan = span;

  [self pushViewInfoToAutoLayoutManagers: info];
}

- (int) rowSpanForView: (NSView *)aView
{
  GSAutoLayoutGridViewInfo *info = [self infoForView: aView];
  return info->_rowSpan;
}

- (void) setColumnSpan: (int)span  
	       forView: (NSView *)aView
{
  GSAutoLayoutGridViewInfo *info = [self infoForView: aView];
  info->_columnSpan = span;

  [self pushViewInfoToAutoLayoutManagers: info];
}

- (int) columnSpanForView: (NSView *)aView
{
  GSAutoLayoutGridViewInfo *info = [self infoForView: aView];
  return info->_columnSpan;
}

- (void) setProportion: (float)proportion  forRow: (int)row
{
  [_rowManager setMinimumLength: 0
	       alwaysExpands: NO
	       neverExpands: NO
	       proportion: proportion
	       ofLinePartAtIndex: row];
}

- (float) proportionForRow: (int)row
{
  return [_rowManager proportionOfLinePartAtIndex: row];
}

- (void) setProportion: (float)proportion  forColumn: (int)column
{
  [_columnManager setMinimumLength: 0
		  alwaysExpands: NO
		  neverExpands: NO
		  proportion: proportion
		  ofLinePartAtIndex: column];
}

- (float) proportionForColumn: (int)column
{
  return [_columnManager proportionOfLinePartAtIndex: column];
}


- (GSAutoLayoutAlignment) autolayoutDefaultHorizontalAlignment
{
  if (_hExpand)
    {
      return GSAutoLayoutExpand;
    }
  else if (_hWeakExpand)
    {
      return GSAutoLayoutWeakExpand;
    }
  else
    {
      return GSAutoLayoutAlignCenter;
    }
}

- (GSAutoLayoutAlignment) autolayoutDefaultVerticalAlignment
{
  if (_vExpand)
    {
      return GSAutoLayoutExpand;
    }
  else if (_vWeakExpand)
    {
      return GSAutoLayoutWeakExpand;
    }
  else
    {
      return GSAutoLayoutAlignCenter;
    }
}

- (float) autolayoutDefaultHorizontalBorder
{
  return 0;
}

- (float) autolayoutDefaultVerticalBorder
{
  return 0;
}

- (void) sizeToFitContent
{
  [self setFrameSize: [self minimumSizeForContent]];
}

- (NSSize) minimumSizeForContent
{
  /* Get it from the autolayout managers.  */
  NSSize minimum;
  minimum.height = [_rowManager minimumLineLength];
  minimum.width = [_columnManager minimumLineLength];

  return minimum;
}

- (void) setDisplayAutoLayoutContainers: (BOOL)flag
{
  [super setDisplayAutoLayoutContainers: flag];
  _displayAutoLayoutContainers = flag;
  [self setNeedsDisplay: YES];
}

- (void) drawRect: (NSRect)exposedRect
{
  if (_displayAutoLayoutContainers)
    {
      /* Draw a red line around ourselves.  */
      NSRect bounds = [self bounds];

      [[NSColor redColor] set];
      NSFrameRect (bounds);

      /* Draw dotted red lines to display where we separate the
       * various boxes.  */
      
      /* First, go over all the columns, and draw a vertical line
       * between each column and the next one.  */
      {
	int i, count = [_columnManager linePartCount];

	for (i = 0; i < count; i++)
	  {
	    GSAutoLayoutSegmentLayout s;
	    
	    s = [_columnManager layoutOfLinePartAtIndex: i];
	    
	    if (i > 0)
	      {
		/* We draw a dashed line between each line part and
		 * the previous one.  */
		NSBezierPath *path;
		static const CGFloat dash[2] = { 1.0, 2.0 };
		
		path = [NSBezierPath bezierPath];
		[path setLineDash: dash  count: 2  phase: 0.0];
		[path moveToPoint: NSMakePoint (s.position, NSMinY (bounds))];
		[path lineToPoint: NSMakePoint (s.position, NSMaxY (bounds))];
		[path stroke];
	      }
	  }
      }

      /* Do the same for the rows.  */
      {
	int i, count = [_rowManager linePartCount];

	for (i = 0; i < count; i++)
	  {
	    GSAutoLayoutSegmentLayout s;
	    
	    s = [_rowManager layoutOfLinePartAtIndex: i];
	    
	    if (i > 0)
	      {
		/* We draw a dashed line between each line part and
		 * the previous one.  */
		NSBezierPath *path;
		static const CGFloat dash[2] = { 1.0, 2.0 };
		
		path = [NSBezierPath bezierPath];
		[path setLineDash: dash  count: 2  phase: 0.0];
		[path moveToPoint: NSMakePoint (NSMinX (bounds), s.position)];
		[path lineToPoint: NSMakePoint (NSMaxX (bounds), s.position)];
		[path stroke];
	      }
	  }
      }
    }
}

@end