"

 COPYRIGHT (c) 1989 by Claus Gittinger

	      All Rights Reserved

 This software is furnished under a license and may be used

 only in accordance with the terms of that license and with the

 inclusion of the above copyright notice.   This software may not

 be provided or otherwise made available to, or used by, any

 other person.  No title to or ownership of the software is

 hereby transferred.

"

View subclass:#ObjectView

	instanceVariableNames:'contents sorted lastButt pressAction releaseAction

		shiftPressAction doublePressAction motionAction keyPressAction

		selection gridShown gridPixmap scaleMetric dragObject

		leftHandCursor oldCursor movedObject moveStartPoint moveDelta

		documentFormat canDragOutOfView rootMotion rootView aligning

		gridAlign aligningMove'

	classVariableNames:''

	poolDictionaries:''

	category:'Views-Basic'

!

!ObjectView class methodsFor:'documentation'!

copyright

"

 COPYRIGHT (c) 1989 by Claus Gittinger

	      All Rights Reserved

 This software is furnished under a license and may be used

 only in accordance with the terms of that license and with the

 inclusion of the above copyright notice.   This software may not

 be provided or otherwise made available to, or used by, any

 other person.  No title to or ownership of the software is

 hereby transferred.

"

!

documentation

"

    a View which can hold DisplayObjects, can make selections, move them around etc.

    this is an abstract class providing common mechanisms - actual instances are

    DrawView, DirectoryView, LogicView or DocumentView.

    [Instance variables:]

        contents        <Collection>            the objects. The order in which

                                                these are in that collection defines

                                                their appearance in the z-plane:

                                                an object located after another one

                                                here will be drawn ABOVE the other.

        sorted          <Boolean>               if set, redraw and picking methods

                                                assume that the objects are sorted by 

                                                >= y-coordinates. These operations are

                                                a bit faster then, since a binary search

                                                can be done. (use with care).

        lastButt        <Point>                 last pointer press position

                                                (internal)

        pressAction     <Block>                 action to perform when mouse pointer

                                                is pressed. Can be set to something like

                                                [self startCreate], [self startSelectOrMove]

                                                etc.

        releaseAction   <Block>                 action to perform when mouse pointer is

                                                released. Typically set in one of the

                                                startXXX methods.

        shiftPressAction        <Block>         like pressAction, if shift key is

                                                pressed.

        doublePressAction       <Block>         same for double-clicks

        motionAction            <Block>         action to perform on mouse-pointer

                                                motion.

        keyPressAction          <Block>         action for keyboard events

        selection               <any>           the current selection; either a single

                                                object or a collection of objects.

        gridShown               <Boolean>       internal

        gridPixmap              <Form>          internal

        scaleMetric             <Symbol>        either #mm or #inch; used to

                                                decide how the grid is defined

        dragObject                              internal

        leftHandCursor                          cursor shown while dragging a rectangle

        oldCursor                               saved original cursor while dragging a rectangle

        movedObject                             internal

        moveStartPoint                          internal

        moveDelta                               internal

        documentFormat          <Symbol>        defines the size and layout of the

                                                document. Can be any of

                                                #letter, #a4, #a3 etc.

        canDragOutOfView        <Boolean>       if true, objects can be dragged out of the

                                                view. If false, dragging is restricted to within

                                                this view.

        rootMotion                              internal

        rootView                                internal

        aligning                <Boolean>       if true, pointer positions are

                                                aligned (snapped) to the point

                                                specified in gridAlign

        gridAlign               <Point>         if aligning is true, this point

                                                defines the snapping. For example,

                                                12@12 defines snap to the nearest

                                                12-point grid.

    written spring/summer 89 by claus

    [author:]

        Claus Gittinger

    [see also:]

        DrawTool LogicTool

        DrawObject

        DisplayObject

"

!

examples

"

    typically, ObjectViews are not used on their own, but instead

    subclassed and thereby provide the common functionality for

    views which show (possibly overlapping) objects.

    The methods here provide all mechanisms to handle redraws, picking

    (i.e. finding an object by position), gridding, moving objects with

    minimum redraw etc.

    Also, zooming and scrolling is handled.

    All objects which respond to the DisplayObject protocol can be handled

    by ObjectView - therefore, you can add almost any object and have it

    displayed and handled here. (as an example, try to copy a LogicGate

    from a LogicView and paste it into a DrawTool - it will work).

    Reminder: ObjectViews are not to be used as below, but instead to be

    subclassed. Therefore, the examples below are somewhat untypical.

    simple example:

                                                                        [exBegin]

        |v o|

        v := ObjectView new.

        v extent:200@200.

        o := DrawRectangle new.

        o origin:10@10 corner:100@100.

        v add:o.

        o := DrawText new.

        o text:'hello there'; origin:50@50; foreground:Color red.

        v add:o.

        v open

                                                                        [exEnd]

    add scrolling:

                                                                        [exBegin]

        |v top o|

        top := HVScrollableView for:ObjectView.

        top extent:200@200.

        v := top scrolledView.

        o := DrawRectangle new.

        o origin:10@10 corner:100@100.

        v add:o.

        o := DrawText new.

        o text:'hello there'; origin:50@50; foreground:Color red.

        v add:o.

        top open

                                                                        [exEnd]

    or, using miniscrollers:

                                                                        [exBegin]

        |v top o|

        top := HVScrollableView for:ObjectView 

                                miniScrollerH:true miniScrollerV:true.

        top extent:200@200.

        v := top scrolledView.

        o := DrawRectangle new.

        o origin:10@10 corner:100@100.

        v add:o.

        o := DrawText new.

        o text:'hello there'; origin:50@50; foreground:Color red.

        v add:o.

        top open

                                                                        [exEnd]

    grid:

                                                                        [exBegin]

        |v top o|

        top := HVScrollableView for:ObjectView 

                                miniScrollerH:true miniScrollerV:true.

        top extent:200@200.

        v := top scrolledView.

        v showGrid.

        o := DrawRectangle new.

        o origin:10@10 corner:100@100.

        v add:o.

        o := DrawText new.

        o text:'hello there'; origin:50@50; foreground:Color red.

        v add:o.

        top open

                                                                        [exEnd]

    zoom:

                                                                        [exBegin]

        |v top o|

        top := HVScrollableView for:ObjectView 

                                miniScrollerH:true miniScrollerV:true.

        top extent:200@200.

        v := top scrolledView.

        v showGrid.

        o := DrawRectangle new.

        o origin:10@10 corner:100@100.

        v add:o.

        o := DrawText new.

        o text:'hello there'; origin:50@50; foreground:Color red.

        v add:o.

        top open.

        Delay waitForSeconds:5.

        v zoom:2.

        Delay waitForSeconds:5.

        v zoom:0.35.

        Delay waitForSeconds:5.

        v zoom:1.

                                                                        [exEnd]

   private benchmark: display 10000 objects ...

                                                                        [exBegin]

        |v top o rnd|

        top := HVScrollableView for:ObjectView 

                                miniScrollerH:true miniScrollerV:true.

        top extent:200@200.

        v := top scrolledView.

        rnd := Random new.

        1000 timesRepeat:[

            o := DrawLine new.

            o origin:(rnd nextIntegerBetween:0 and:700) @ (rnd nextIntegerBetween:0 and:700)

              corner:(rnd nextIntegerBetween:0 and:700) @ (rnd nextIntegerBetween:0 and:700).

            v add:o.

        ].

        top openAndWait.

            Time millisecondsToRun:[

                v redraw              

            ])

                                                                        [exEnd]

"

! !

!ObjectView class methodsFor:'defaults'!

hitDelta

    "when clicking an object, allow for hitDelta pixels around object;

     0 is exact; 1*pixelPerMillimeter is good for draw programs"

    ^ 0

! !

!ObjectView methodsFor:'adding / removing'!

add:something

    "add something, anObject or a collection of objects to the contents

     with redraw"

    self forEach:something do:[:anObject |

	self addObject:anObject

    ]

!

addObject:anObject

    "add the argument, anObject to the contents - with redraw"

    anObject notNil ifTrue:[

	contents addLast:anObject.

	"its on top - only draw this one"

	shown "realized" ifTrue:[

	    self showUnselected:anObject

	]

    ]

!

addObjectWithoutRedraw:anObject

    "add the argument, anObject to the contents - no redraw"

    anObject notNil ifTrue:[

	contents addLast:anObject

    ]

!

addSelected:something

    "add something, anObject or a collection of objects to the contents

     and select it"

    self add:something.

    self select:something

!

addWithoutRedraw:something

    "add something, anObject or a collection of objects to the contents

     do not redraw"

    self forEach:something do:[:anObject |

	self addObjectWithoutRedraw:anObject

    ]

!

remove:something

    "remove something, anObject or a collection of objects from the contents

     do redraw"

    something size > (contents size / 4) ifTrue:[

	"

	 better to remove first, then redraw rest

	"

	self forEach:something do:[:anObject |

	    self removeFromSelection:anObject.

	    contents remove:anObject.

	].

	self redraw.

	^ self

    ].

    self forEach:something do:[:anObject |

	self removeObject:anObject

    ]

!

removeAll

    "remove all - redraw"

    self removeAllWithoutRedraw.

    self redraw

!

removeAllWithoutRedraw

    "remove all - no redraw"

    selection := nil.

    contents := OrderedCollection new

!

removeObject:anObject

    "remove the argument, anObject from the contents - no redraw"

    anObject notNil ifTrue:[

	self removeFromSelection:anObject.

	contents remove:anObject.

	shown "realized" ifTrue:[

	    self redrawObjectsIn:(anObject frame)

	]

    ]

!

removeObjectWithoutRedraw:anObject

    "remove the argument, anObject from the contents - no redraw"

    anObject notNil ifTrue:[

	self removeFromSelection:anObject.

	contents remove:anObject

    ]

!

removeWithoutRedraw:something

    "remove something, anObject or a collection of objects from the contents

     do not redraw"

    self forEach:something do:[:anObject |

	self removeObjectWithoutRedraw:anObject

    ]

! !

!ObjectView methodsFor:'cut & paste '!

convertForPaste:anObject

    "return a converted version of anObject to be pasted, or nil if

     the object is not compatible with me.

     Return nil here; concrete subclasses should try to convert.

     Notice: anObject may be a collection of to-be-pasted objects."

    "in concrete subclasses, you can use:"

"

    |s|

    (anObject respondsTo:#asDisplayObject) ifTrue:[

	^ anObject asDisplayObject

    ].

    (anObject isString or:[anObject isMemberOf:Text]) ifTrue:[

    ].

    anObject size > 0 ifTrue:[

	(anObject inject:true into:[:okSoFar :element |

	    okSoFar and:[element respondsTo:#asDisplayObject]

	]) ifFalse:[

	    self warn:'selection not convertable to DisplayObject'.

	    ^ nil

	].

	^ anObject collect:[:element | element asDisplayObject].

    ].

"

    ^ nil.

!

copySelection

    "copy the selection into the cut&paste-buffer"

    |tmp|

    tmp := OrderedCollection new.

    self selectionDo:[:object |

	tmp add:(object copy)

    ].

"/    self forEach:tmp do:[:anObject |

"/        anObject moveTo:(anObject origin + (8 @ 8))

"/    ].

    self setSelection:tmp

!

deleteSelection

    "delete the selection into the cut&paste buffer"

    |tmp|

    tmp := selection.

    self unselect.

    self remove:tmp.

    self setSelection:tmp

!

paste:something

    "add the objects in the cut&paste-buffer"

    |s|

    self unselect.

    s := self convertForPaste:something .

    s isNil ifTrue:[

	self warn:'selection not convertable'.

	^ self

    ].

    self addSelected:s 

!

pasteBuffer

    "add the objects in the paste-buffer"

    |sel|

    sel := self getSelection.

    (device getSelectionOwnerOf:(device atomIDOf:'PRIMARY')) == drawableId

    ifTrue:[

	"

	 a local selection - paste with some offset

	"

	sel size > 0 ifTrue:[

	    sel := sel collect:[:element |

		element copy moveTo:(element origin + (8 @ 8))

	    ]