File: magnifyclass.doc Description: MagnifyClass documentation. Copyright: (C) Copyright 1995/96 Reinhard Katzmann. All Rights Reserved. This class is FREEWARE. ------------------------------------------------------------------------------ TABLE OF CONTENTS magnifyclass/--background-- magnifyclass/Methods magnifyclass/Attributes magnifyclass/--background-- magnifyclass/--background-- NAME Class: magnifyclass Superclass: baseclass Include File: "MagnifyClass.h" FUNCTION To provide you with a picture gadget which uses bitmaps as picture data instead of Intuition Images. It allows you to magnify the picture and to show you only a region of the whole bitmap if you want to. It also lets you edit the picture or to only view the picture. Objects from this class send out the following attribute pairs in their notification messages: GA_ID: - Gadget object ID MAGNIFY_MagFactor - The current magnification factor MAGNIFY_FrameCoordsX - The current X-coordinate of a framed point MAGNIFY_FrameCoordsX - The current Y-coordinate of a framed point MAGNIFY_PicArea - The current Picture (bitmap) area MAGNIFY_SelectRegionX - The currently selected X-coordinate MAGNIFY_SelectRegionY - The currently selected Y-coordinate NOTE This class is provided as source code. To make use of this class you must compile it into an object module and link it in with your main program. Also your program must open the following libraries: intuition.library - V37 or better. graphics.library - V37 or better. utility.library - V37 or better. bitmap.library - V1.3 or better. bgui.library - V39 or better. Ofcourse these libraries must remain open until you are done using the class. magnifyclass/Methods magnifyclass/Methods NEW METHODS MAGM_Undo -- This method tells the class to undo the last operation on the MAGNIFY_PicArea (direct set, last user edit operation). MAGM_AllocBitMap -- Internal methods for allocating bitmap. Do _not_ MAGM_FreeBitMap use them because they will be obsolete in a future version (it will use BGUI_Alloc/FreeBitMap() which are V40 bgui.library functions. CHANGED METHODS None. magnifyclass/Attributes magnifyclass/Attributes NOTE All baseclass attributes are also valid for this class. NAME MAGNIFY_MagFactor -- ( UWORD ) FUNCION This is the magnification factor of the magnify object. If you set it the class will immediately change the picture to show you the magnified part which fits into the object bounds. The attribute MAGNIFY_Grid also causes another change of the magnification. Default is 1 (no magnification). Applicability is (ISGNU). SEE ALSO MAGNIFY_Grid NAME MAGNIFY_Edit -- ( BOOL ) FUNCTION This attribute selects the kind of the Magnify object. If set to TRUE the user is allowed to draw in it with the mouse. Drawing is done with the left mouse button. If set to FALSE it is a view only gadget. Defalt is TRUE (Drawing is allowed). Applicability is (IG) NAME MAGNIFY_SpecialFrame -- ( BOOL ) FUNCTION To allow you to have a point with a frame around it. This is mainly thought to be used in sprite or bob editors whose graphic objects are later controlled by mouse or joystick (like the "Hot Spot" in the Pointer Preferences ). Note that the point is only framed when MAGNIFY_Grid == TRUE. Default is FALSE (no framed pointer). Applicability is (IG). BUGS I never tested this attribute. SEE ALSO MAGNIFY_FrameCoordsX MAGNIFY_FrameCoordsY MAGNIFY_Grid NAME MAGNIFY_GraphWidth -- ( UWORD ) MAGNIFY_GraphHeight -- ( UWORD ) FUNCTION These attributes specify the Width and the Height of the picture area (better: bitmap area of the window object). They must be set to use the object at all. These attributes are used to set the picture area in which the picture will be rendered. Defaults are MINCOL for MAGNIFY_GraphWidth and MINROW for MAGNIFY_GraphHeight Applicability is (IG) WARNING Don't assume anything about the real defaults values. They are subject to change or even dissappear in the future and might be replaced by an "error and exit" message. FURTHER NOTES Until know it is not possible to change the picture area size om the fly. This is theoretically possible, but needs some overhead. Please let me know if this is important to you. SEE ALSO MAGNIFY_PicArea NAME MAGNIFY_FrameCoordsX -- ( UWORD ) MAGNIFY_FrameCoordsY -- ( UWORD ) FUNCTION To specify the X- and Y-coordinates on which the framed pointer will appear. Note that this is not done automatically like editing. Defaults are 0. Applicability is (ISGNU) SEE ALSO MAGNIFY_SpecialFrame NAME MAGNIFY_PicArea -- ( struct BitMap * ) FUNCTION This attribute is used to set the whole picture Area and its bitmap. The BitMap has to be fully initialized and allocated. If a picture is already in the BitMap it will be shown after building the gadget. This is also the way to change the picture of the gadget. The object allocates its own BitMap so you can free your BitMap after having set / initialized it into the object. If there already was a picture in the BitMap it will be copied into a (new allocated) BitMap which works as an undo buffer. This buffer can be restored using the MAGM_Undo method. When using V39+ of the OS the object allocates the bitmap using the GetBitMapAttr() function, so there should be no problem with special bitmaps (as long as they work with ScaleBitMap()). Default is NULL. Applicability is (ISGNU) SEE ALSO MAGNIFY_SelectRegionX MAGNIFY_SelectRegionY NAME MAGNIFY_CurrentPen -- ( UBYTE ) FUNCTION To set or change the current Pen Color which is used in drawing mode. This is useful in conjunction with a palette gadget :-). Default is 0. Applicability is (ISGU) WARNING 24 Bit Palettes or HAM Mode are not supported by this class. SEE ALSO MAGNIFY_Edit NAME MAGNIFY_Grid -- ( BOOL ) FUNCTION To enable the GRID Mode of the Class. This creates a square around each pixel. The magnification of the object is therefore doubled. The grid will be drawm in the current Grid color. Default is FALSE (no Grid mode). Applicability is (ISGNU) SEE ALSO MAGNIFY_MagFactor MAGNIFY_GridPen NAME MAGNIFY_GridPen ( UBYTE ) FUNCTION This attribute sets or changes the Pen in which the Grid is drawn. Default is 0 ("invisible"). Applicability is (ISGNU) WARNING 24 Bit Palettes or HAM Mode are not supported by this class. SEE ALSO MAGNIFY_Grid NAME MAGNIFY_SelectRegionX -- ( UWORD ) MAGNIFY_SelectRegionY -- ( UWORD ) FUNCTION To change the X- and Y-Coordinates of the picture area. These are the real coodinates of the picture bitmap of the object. This way you can scroll around in the whole picture. (Note that scrolling itself is not very fast and can't be optimized with much overhead.) Defaults are 0. Applicability is (ISGNU)