This is DragView.m in view mode; [Download] [Up]
//
// A View that implements Dragging in 3.0
// Greg Burd
// Copyright NeXT Computer, Inc 1992 All Rights Reserved
//
// Created 7-4-92 -- (Improved from existing code by Randy Nelson)
//
// You may freely copy, distribute and reuse the code in this example.
// NeXT disclaims any warranty of any kind, expressed or implied, as to
// its fitness for any particular use.
//
#import "DragView.h"
#import "Text_Console.h" // text category that allows formated printf:
#import <appkit/Application.h>
#import <appkit/Pasteboard.h>
#import <appkit/OpenPanel.h>
#import <appkit/graphics.h> // for NXFrameRectWithWidth
@implementation DragView
/*-------------------- methods to get things set up */
- initFrame:(const NXRect *)theFrame
{
const char *const types[] = {NXPostScriptPboardType};
[textObj printf:"In initFrame:\n"];
[super initFrame:theFrame];
//register which pasteboard types you will accept
[self registerForDraggedTypes:(const char *const*)&types count:1];
drawBackground = YES;
return self;
}
- awakeFromNib
{
[textObj printf:"In awakeFromNib:\n"];
framed = NO;
[window makeKeyAndOrderFront:self];
return self;
}
/*-------------------- methods to be the source of a dragging operation */
- mouseDown:(NXEvent *)theEvent
{
NXPoint zero = {0.0, 0.0};
id thePboard;
[textObj printf:"In mouseDown:\n"];
// Prevent default window ordering (this is a new appkit feature)
[NXApp preventWindowOrdering];
//get the Pboard
thePboard = [Pasteboard newName:NXDragPboard];
[thePboard declareTypes:&NXPostScriptPboardType num:1 owner:self];
//put an EPS of the image on the Pboard
drawBackground = NO;
[self writePSCodeInside:&bounds to:thePboard];
drawBackground = YES;
//start the drag
[self dragImage:theImage // visable on screen during drag
at:&zero // offset the mouse point for the drag
offset:&zero // offset the inital mouse pt
event:theEvent // theEvent structure
pasteboard:thePboard // a Pasteboard with data on it
source:self // source object
slideBack:YES]; // if no destination animate back to source
return self;
}
- draggedImage:(NXImage *)image beganAt:(NXPoint *)screenPoint
{
[textObj printf:"In draggedImage::\n"];
return self;
}
- (NXDragOperation)draggingSourceOperationMaskForLocal:(BOOL)flag
{
[textObj printf:"In draggingSourceOperationMaskForLocal:\n"];
return (NX_DragOperationCopy | NX_DragOperationGeneric);
}
- draggedImage:(NXImage *)image endedAt:(NXPoint *)screenPoint deposited:(BOOL)flag
{
[textObj printf:"In draggedImage:\n"];
return self;
}
/*-------------------- methods to be the destination of a dragging operation */
- (NXDragOperation)draggingEntered:sender
{
[textObj printf:"In draggingEntered:\n"];
// check to make sure we are not the source and this operation is a copy
if (([sender draggingSourceOperationMask] & NX_DragOperationCopy) &&
([sender draggingSource] != self)) {
framed = YES;
[self display];
//return the type of operation we want to do, this will dictate
//the type of cursor will show up when accepting the drag
return NX_DragOperationCopy;
}
return NX_DragOperationNone;
}
- (NXDragOperation)draggingUpdated:sender
{
[textObj printf:"In draggingUpdated:\n"];
// make sure that this is a copy operation, and that this instance
// of DragView is not the source
if (([sender draggingSourceOperationMask] & NX_DragOperationCopy) &&
([sender draggingSource] != self)) {
framed = YES;
[self display];
return NX_DragOperationCopy;
}
return NX_DragOperationNone;
}
- draggingExited:sender
{
[textObj printf:"In draggingExited:\n"];
if (framed) {
framed = NO;
[self display];
}
return self;
}
- (BOOL)prepareForDragOperation:sender
{
[textObj printf:"In performDragOperation:\n"];
return YES;
}
- (BOOL)performDragOperation:sender
{
[textObj printf:"In performDragOperation:\n"];
// make sure that what we are getting is from the same application
// and did not originate from this view.
if ([sender isDraggingSourceLocal] && ([sender draggingSource] != self)) {
// if I had an image free it
if (theImage) [theImage free];
// new call in NXImage allows you to initFromPasteboard
theImage = [[NXImage alloc] initFromPasteboard:
[sender draggingPasteboard]];
[theImage setDataRetained:YES]; // otherwise it scales poorly
[theImage setScalable:YES]; // scaleable yes
[theImage setSize:&bounds.size];// rescale to the same size as view
framed = NO;
[self display];
}
if(framed) {
framed = NO;
[self display];
}
return YES;
}
- concludeDragOperation:sender
{
[textObj printf:"In concludeDragOperation:\n"];
// This is within a oneway call, so you can send a call to Workspace
// without it getting 'hung up' waiting for a return
return self;
}
/*-------------------- methods to display, and other useful stuff */
- (BOOL)acceptsFirstMouse
{
[textObj printf:"In acceptsFirstMouse:\n"];
return YES;
}
- (BOOL)shouldDelayWindowOrderingForEvent:(NXEvent *)theEvent
{
// This is the other portion of the new appkit functionality
// which allows you to drag a partially obscure object without
// making the source window become main, and without making the
// source application the current app.
[textObj printf:"In shouldDelayWindowOrderingForEvent:\n"];
return YES;
}
- sizeTo:(NXCoord)x :(NXCoord)y
{
[textObj printf:"In sizeTo::\n"];
[super sizeTo:x :y];
[theImage setSize:&bounds.size];
return self;
}
- open:sender
{
static const char *const types[] = {"tiff", "eps", NULL};
[textObj printf:"In open:\n"];
// get a filename to open
if ([[OpenPanel new] runModalForTypes:types] == 0) return nil;
// create an image from the file
// it'll be whatever size the file tells it to be
[self setImage:[[NXImage alloc] initFromFile:[[OpenPanel new] filename]]];
return self;
}
- setImage:(id)anImage
{
[textObj printf:"In setImage:\n"];
// free theImage it if is been used
if(theImage) [theImage free];
framed = NO;
theImage = anImage;
[theImage setScalable:YES]; // scaleable yes
[theImage setSize:&bounds.size]; // rescale to the same size as view
[self display];
return self;
}
- drawSelf:(const NXRect *)rects :(int)num
{
// if we are copying the PS code onto the Pboard, then we don't want
// the white background. Only the image.
if (drawBackground) NXEraseRect(rects);
// Composite the image into the view.
[theImage composite:NX_SOVER toPoint:&bounds.origin];
// if we are in the middle of a drag operation then we can frame the
// view rect to show our acceptance of the incomming data. Another way
// would be to create a ghost image similar to the shelf in Workspace.
if(framed) {
NXFrameRectWithWidth(&bounds, (NXCoord)3.0);
}
return self;
}
- free
{
[textObj printf:"In free:\n"];
// be a good object and free things up
[theImage free];
return [super free];
}
@end
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