/*

MarginView.h

Copyright (c) 2002 OpenBeOS.

Authors:
	Philippe Houdoin
	Simon Gauvin
	Michael Pfeiffer

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is furnished to do
so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.

	Documentation:

	The MarginView is designed to be a self contained component that manages
	the display of a BBox control that shows a graphic of a page and its'
	margings. The component also includes text fields that are used to mofify
	the margin values and a popup to change the units used for the margins.

	There are two interfaces for the MarginView component:

	1) Set methods:
		- page size
		- orientation

	   Get methods to retrieve:
		- margins
		- page size

		The method interface is available for the parent Component to call on
		the MarginView in response to the Window receiveing messages from
		other BControls that it contains, such as a Page Size popup. The
		Get methods are used to extract the page size and margins so that
		the printer driver may put these values into a BMessage for printing.

	2) 'Optional' Message interface:
		- Set Page Size
		- Flip Orientation

		The message interface is available for GUI Controls, BPopupMenu to send
		messages to the MarginView if the parent Window is not used to handle
		the messages.

	General Use of MarginView component:

		1) Simply construct a new MarginView object with the margins
			you want as defaults and add this view to the parent view
			of the dialog.

			MarginView *mv;
			mv = new MarginView(viewSizeRect, pageWidth, pageHeight);
			parentView->AddChild(mv);

			* you can also set the margins in the constructor, and the units:

			mv = new MarginView(viewSizeRect, pageWidth, pageHeight
						marginRect, kUnitPointS);

			! but remeber to have the marginRect values match the UNITS :-)

		2) Set Page Size with methods:

			mv-SetPageSize( pageWidth, pageHeight );
			mv->UpdateView();

		3) Set Page Size with BMessage:

			BMessage* msg = new BMessage(CHANGE_PAGE_SIZE);
			msg->AddFloat("width", pageWidth);
			msg->AddFloat("height", pageHeight);
			mv->PostMessage(msg);

		4) Flip Page with methods:

			mv-SetPageSize( pageHeight, pageWidth );
			mv->UpdateView();

		5) Flip Page with BMessage:

			BMessage* msg = new BMessage(FLIP_PAGE);
			mv->Looper()->PostMessage(msg);

		Note: the MarginView DOES NOT keep track of the orientation. This
				should be done by the code for the Page setup dialog.

		6) Get Page Size

			BPoint pageSize = mv->GetPageSize();

		7) Get Margins

			BRect margins = mv->GetMargins();

		8) Get Units

			uint32 units = mv->GetUnits();

			where units is one of:
				kUnitInch,  72 points/in
				kUnitCM,    28.346 points/cm
				kUnitPoint, 1 point/point
*/

#ifndef _MARGIN_VIEW_H
#define _MARGIN_VIEW_H

#include <InterfaceKit.h>
#include <Looper.h>

class BTextControl;
class MarginManager;

// Messages that the MarginManager accepts
const uint32 TOP_MARGIN_CHANGED    = 'tchg';
const uint32 RIGHT_MARGIN_CHANGED  = 'rchg';
const uint32 LEFT_MARGIN_CHANGED   = 'lchg';
const uint32 BOTTOM_MARGIN_CHANGED = 'bchg';
const uint32 MARGIN_CHANGED        = 'mchg';
const uint32 CHANGE_PAGE_SIZE      = 'chps';
const uint32 FLIP_PAGE             = 'flip';
const uint32 MARGIN_UNIT_CHANGED   = 'mucg';

enum MarginUnit {
	kUnitInch = 0,
	kUnitCM,
	kUnitPoint
};

/**
 * Class MarginView
 */
class MarginView : public BBox
{
friend class MarginManager;

public:
							MarginView(BRect rect, int32 pageWidth = 0,
								int32 pageHeight = 0,
								BRect margins = BRect(1, 1, 1, 1), // 1 inch
								MarginUnit unit = kUnitInch);

	virtual					~MarginView();

	virtual	void			AttachedToWindow();
	virtual	void			Draw(BRect rect);
	virtual	void			FrameResized(float width, float height);
	virtual	void			MessageReceived(BMessage *msg);

			// point.x = width, point.y = height
			BPoint			PageSize() const;
			void			SetPageSize(float pageWidth, float pageHeight);

			// margin
			BRect			Margin() const;

			// units
			MarginUnit		Unit() const;

			// will cause a recalc and redraw
			void			UpdateView(uint32 msg);

private:
			// all the GUI construction code
			void			_ConstructGUI();

			// utility method
			void			_AllowOnlyNumbers(BTextControl *textControl,
								int32 maxNum);

			// performed internally using text fields
			void			_SetMargin(BRect margin);

			// performed internally using the supplied popup
			void			_SetMarginUnit(MarginUnit unit);

			// Calculate the view size for the margins
			void			_CalculateViewSize(uint32 msg);

private:
			BTextControl*	fTop;
			BTextControl*	fBottom;
			BTextControl*	fLeft;
			BTextControl*	fRight;

			// rect that holds the margins for the page as a set of point offsets
			BRect			fMargins;

			// the maximum size of the page view calculated from the view size
			float			fMaxPageWidth;
			float			fMaxPageHeight;

			// the actual size of the page in points
			float			fPageHeight;
			float			fPageWidth;

			// the units used to calculate the page size
			MarginUnit		fMarginUnit;
			float			fUnitValue;

			// the size of the drawing area we have to draw the view in pixels
			float			fViewHeight;
			float			fViewWidth;
};

#endif // _MARGIN_VIEW_H