TweetFollow Us on Twitter

Resize Objects
Volume Number:7
Issue Number:4
Column Tag:Jörg's Folder

Related Info: Quickdraw

Getting A Handle On Objects

By Jörg Langowski, MacTutor Editorial Board

Note: Source code files accompanying article are located on MacTech CD-ROM or source code disks.

“C++/MacApp - resizing objects”

As promised last month, this time we’ll start adding some code to our MacApp drawing program to change the basic shapes once they’ve been drawn. I have chosen to implement a resize operation; other functions, like changing colors and patterns, manipulating the order of objects, etc., will follow later.

We are going to use an interface similar to MacDraw, where a selected object has a number of small black squares connected with itself that can be used to change its shape. We’ll call them ‘tags’ in the following. Objects that can be circumscribed by a rectangle have eight tags: four on the corners and four on the centers of the edges. Dragging a corner tag will move the two sides of the rectangle adjacent to the corner, while dragging the edge tag will only move the side of the rectangle that contains the tag.

We’ll need code to display the tags, determine whether the mouse was clicked in one of them, and take action (track the mouse) depending on what tag it was clicked in. Of course, all operations should be undoable, but that’s almost implicit in MacApp.

Detecting the mouse click will proceed in two stages: first, we’ll check whether the mouse has been clicked in any one of the eight tags. If so, we’ll create a new command object of class TSizer, which then does the mouse tracking and track feedback. The command object determines where the mouse was clicked exactly, and the tracking and action will depend on the tag.

For the first phase - determining whether the mouse was clicked in one of the tags at all - it is convenient to create a region that consists of all the eight tags. This region is stored in a new instance variable of TBox, fTagRgn, and created when an object is selected and redrawn (see changes to the TBox::DrawShape method in listing 3). Also, the eight tags are stored individually as Rect instance variables.

The changes to the mouse down command handler are shown in listing 2. We shall now create a TSketcher, a TDragger, or a TSizer command object, depending on where the mouse was clicked - outside any object, inside a selected object, or inside one of the tags of a selected object.

In the TSizer::TrackMouse method we determine which of the eight tags was clicked in, and allow for changes in the top, bottom, left and right coordinates of the object (flags pT, pB, pL, pR). While those coordinates are continuously changed in the TrackMove phase of the TrackMouse method, the TrackFeedback method simply redraws the object rectangle in XOR mode. Undoing can be implemented very simply by remembering the old coordinates of the object.

Sounds simple? It is, and again the modifications are only to a very limited part of the total code - one of MacApp’s great advantages. We still have to add one more ‘Buzzword’ to the list of commands that appear after the Undo/Redo menu item (Listing 4), and extend the Make file a little. By now our code has grown too big to fit into one segment (compiling in Debug mode). Thus, you’ll also see how to segment a MacApp program.

I have put the code that is supposed to go into the new segment into the file TBox.cp, containing TSizer and all the Box/Shape classes. We then have to tell the MacApp builder that this file should be linked in under a different segment name. The necessary changes are shown in listing 5. We add the name of the new source file (TBox.cp) to the list of OtherInterfaces, and the corresponding object file (TBox.cp.o) to the list of OtherLinkFiles. Last, we add the dependency rule for generating the object file (also containing a comment line showing the build progress).

The drawing example will certainly still be extended over the next few months, but we’ll also take up some Forth again soon. Until then.

Listing 1: Changes to TEDrag.h

class TBox : public TObject {
public:
 Rect fLocation;
 BooleanfSelected;
 RgnHandlefTagRgn;
 Rect fTL,fTR,fBL,fBR,
 fT,fB,fL,fR;
 virtual pascal void IBox(Rect *itsLocation);
 virtual pascal void DrawShape();
 virtual pascal void NeedDiskSpace(long *data);
 virtual pascal void Read(short aRefNum);
 virtual pascal void Write(short aRefNum);
#ifdef qDebug
 virtual pascal void Fields(pascal void (*DoToField) 
 (StringPtr fieldName, Ptr fieldAddr, 
 short fieldType, void *link), void *link);
#endif
};

class TSizer : public TCommand {
public:
 TTEDocument   *fTEDocument;
 TTextView*fTextView;
 TBox   *fBox;   RectoldLocation;  RectnewLocation;      Point 
 fStart;  // mouse pressed here
 Point  fDelta;  // offset moved
 BooleanpT,pB,pL,pR; 
 // flags to indicate which coordinates to change
 pascal void ISizer(TBox *itsBox, 
 TTEDocument *itsDocument, TTextView *itsView);
 pascal struct TCommand *TrackMouse
 (TrackPhase aTrackPhase, VPoint *anchorPoint, 
 VPoint *previousPoint, VPoint *nextPoint, 
 Boolean mouseDidMove);
 pascal void TrackFeedback
 (VPoint *anchorPoint, VPoint *nextPoint,
 Boolean turnItOn, Boolean mouseDidMove);
 pascal void DoIt();
 pascal void RedoIt();
 pascal void UndoIt();
#ifdef qDebug
 virtual pascal void Fields(pascal void (*DoToField) 
 (StringPtr fieldName, Ptr fieldAddr, 
 short fieldType, void *link), void *link);
#endif
};
Listing 2: Change to TTextView::DoMouseCommand (file TEDrag.cp)
   
 if (aFindBoxStruct.myBox->fSelected)
 { if (info->theShiftKey) 
 { aFindBoxStruct.myBox->fSelected = false;
 InvalidRect (&aFindBoxStruct.myBox->fLocation);
 return inherited::DoMouseCommand
 (theMouse,info,hysteresis);   
 }
 else
 { if (PtInRgn(*theMouse,
 aFindBoxStruct.myBox->fTagRgn))
 { aSizer = new TSizer;
 FailNIL(aSizer);
 aSizer->ISizer (aFindBoxStruct.myBox,
  fTEDocument, this);
 return aSizer;   }
 else
 { aDragger = new TDragger;
 FailNIL(aDragger);
 aDragger->IDragger
 (aFindBoxStruct.myBox, fTEDocument, this);
 return aDragger;   }
 }
 }
 else
 {
 if (!info->theShiftKey) 
 { fTEDocument->ForEachShapeDo
 ((DoToObject)Deselect, &aSelectStruct); }
 aFindBoxStruct.myBox->fSelected = true;
 InvalidRect(&aFindBoxStruct.myBox-> fLocation);
 return inherited::DoMouseCommand
 (theMouse,info,hysteresis);
 }
   
Listing 3: TBox.cp
#include <UMacApp.h>
#include <UTEView.h>
#include <ToolUtils.h>
#include “TEDrag.h”

const int kBoxColor= redColor;
const int cSizer = 4001;
// Resizing support, JL 2/91
pascal void TSizer::ISizer(TBox *itsBox, 
 TTEDocument *itsDocument, TTextView *itsView)
{
 TScroller *aScroller;

 aScroller = itsView->GetScroller(true);
 ICommand(cSizer, itsDocument, itsView, aScroller);
 fTEDocument = itsDocument;
 fTextView = itsView;
 fBox = itsBox;  
 pT = false; pB = false; pL = false; pR = false;
 oldLocation = fBox->fLocation;
 newLocation = oldLocation;
}

pascal struct TCommand *TSizer::TrackMouse
 (TrackPhase aTrackPhase, VPoint *anchorPoint, 
 VPoint *previousPoint,  VPoint *nextPoint, 
 Boolean mouseDidMove)
{
 fStart = fTextView->ViewToQDPt(anchorPoint);
 
 if (aTrackPhase == trackPress) {
 if (PtInRect(fStart,&fBox->fTR)) { pT = true; pR = true; }
 else if (PtInRect(fStart,&fBox->fTL))
 { pT = true; pL = true; }
 else if (PtInRect(fStart,&fBox->fBR))
 { pB = true; pR = true; }
 else if (PtInRect(fStart,&fBox->fBL))
 { pB = true; pL = true; }
 else if (PtInRect(fStart,&fBox->fT)) { pT = true; }
 else if (PtInRect(fStart,&fBox->fB)) { pB = true; }
 else if (PtInRect(fStart,&fBox->fL)) { pL = true; }
 else if (PtInRect(fStart,&fBox->fR)) { pR = true; }
 }

 if ((aTrackPhase == trackMove) && mouseDidMove) {
 fDelta = fTextView->ViewToQDPt(nextPoint);
 SubPt(fTextView->ViewToQDPt(anchorPoint), &fDelta);
 
 if ( !((fDelta.h == 0) && (fDelta.v == 0)) ) {                
 if (pT){ newLocation.top = 
 oldLocation.top + fDelta.v;  }
 if (pB){ newLocation.bottom = 
 oldLocation.bottom + fDelta.v; }
 if (pL){ newLocation.left = 
 oldLocation.left + fDelta.h; }
 if (pR){ newLocation.right = 
 oldLocation.right + fDelta.h; }
 }
 }

 if ((aTrackPhase == trackRelease) && mouseDidMove) {
 fDelta = fTextView->ViewToQDPt(nextPoint);
 SubPt(fTextView->ViewToQDPt(anchorPoint), &fDelta);
 if ((fDelta.h == 0) && (fDelta.v == 0))
 { return gNoChanges; }
 fBox->fLocation = newLocation;
 }
 return this;
}

pascal void TSizer::TrackFeedback
 (VPoint *anchorPoint, VPoint *nextPoint,
 Boolean turnItOn, Boolean mouseDidMove)
{
 PenState oldState;
 
 if (mouseDidMove) {
 GetPenState(&oldState);
 PenNormal();
 PenMode(patXor);
 FrameRect(&newLocation);
 SetPenState(&oldState);
 }
}

pascal void TSizer::DoIt()
{fTextView->InvalidRect(&newLocation);
 fTextView->InvalidRect(&oldLocation);   }

pascal void TSizer::RedoIt()  
{  fBox->fLocation = newLocation; DoIt();    }

pascal void TSizer::UndoIt()
{fBox->fLocation = oldLocation; DoIt();      }

#ifdef qDebug
pascal void TSizer::Fields(pascal void (*DoToField) 
 (StringPtr fieldName, Ptr fieldAddr, 
 short fieldType, void *link), void *link)
{
 DoToField(“\pTSizer”, nil, bClass, link);
 DoToField(“\pfTEDocument”, 
 (Ptr) &fTEDocument, bObject, link);
 DoToField(“\pfTextView”, (Ptr) &fTextView, bObject, link);
 DoToField(“\pfBox”, (Ptr) &fBox, bObject, link);
 DoToField(“\poldLocation”, (Ptr) &oldLocation, bRect, link);
 DoToField(“\pnewLocation”, (Ptr) &newLocation, bRect, link);
 DoToField(“\pfStart”, (Ptr) &fStart, bPoint, link);
 DoToField(“\pfDelta”, (Ptr) &fDelta, bPoint, link);
 DoToField(“\ppT”, (Ptr) &pT, bBoolean, link);
 DoToField(“\ppB”, (Ptr) &pB, bBoolean, link);
 DoToField(“\ppL”, (Ptr) &pL, bBoolean, link);
 DoToField(“\ppR”, (Ptr) &pR, bBoolean, link);
 inherited::Fields(DoToField, link);
}
#endif

pascal void TBox::IBox(Rect *itsLocation)
 {    fLocation = *itsLocation; fSelected = false; }

pascal void TBox::DrawShape()
{
 if (fSelected) {
 short halfH, halfV;
 
 halfH = (fLocation.right-fLocation.left)/2;
 halfV = (fLocation.bottom-fLocation.top)/2;
 
 PenSize (1,1);
 ForeColor(blackColor);
 FrameRect(&fLocation);
 
 fTagRgn = MakeNewRgn();
 OpenRgn();
 
 fTL.top = fLocation.top;
 fTL.left = fLocation.left;
 fTL.bottom = fTL.top + 4;
 fTL.right = fTL.left + 4;
 FrameRect(&fTL);
 
 fT.top = fLocation.top;
 fT.bottom = fT.top + 4;
 fT.left = fLocation.left + halfH - 2;
 fT.right = fT.left + 4;
 FrameRect(&fT);
 
 fTR.top = fLocation.top;
 fTR.bottom = fTR.top + 4;
 fTR.right = fLocation.right;
 fTR.left = fTR.right - 4;
 FrameRect(&fTR);
 
 fBL.bottom = fLocation.bottom;
 fBL.top = fBL.bottom - 4;
 fBL.left = fLocation.left;
 fBL.right = fBL.left + 4;
 FrameRect(&fBL);
 
 fB.bottom = fLocation.bottom;
 fB.top = fB.bottom - 4;
 fB.left = fLocation.left + halfH - 2;
 fB.right = fB.left + 4;
 FrameRect(&fB);
 
 fBR.bottom = fLocation.bottom;
 fBR.top = fBR.bottom - 4;
 fBR.right = fLocation.right;
 fBR.left = fBR.right - 4;
 FrameRect(&fBR);
 
 fL.top = fLocation.top + halfV - 2;
 fL.bottom = fL.top + 4;
 fL.left = fLocation.left;
 fL.right = fL.left + 4;
 FrameRect(&fL);
 
 fR.top = fLocation.top + halfV - 2;
 fR.bottom = fR.top + 4;
 fR.right = fLocation.right;
 fR.left = fR.right - 4;
 FrameRect(&fR);
 
 CloseRgn(fTagRgn);
 FillRgn(fTagRgn,qd.black);
 ForeColor(kBoxColor);  }
}
   the rest of the file (TShape and following definitions) stays unchanged 
  
Listing 4: Change to TEDrag.r

#define cSizer   4001
resource ‘cmnu’ (128) {
 128, textMenuProc, allEnabled, enabled, “Buzzwords”,          /* these 
words appear after Undo in the Edit menu */
  {
 “Page Setup Change”, noIcon, noKey, 
 noMark, plain, cChangePrinterStyle;
 “Typing”, noIcon, noKey, noMark, plain, cTyping;
 “Drawing”,  noIcon, noKey, 
 noMark, plain, cDrawBox;
 “Dragging”,  noIcon, noKey, 
 noMark, plain, cDragBox;
 “Resize”,  noIcon, noKey, noMark, plain, cSizer
 }
};
Listing 5: TEDrag.MAMake
AppName = TEDrag
OtherInterfaces =  
 “{SrcApp}TBox.cp”
OtherLinkFiles = 
 “{ObjApp}TBox.cp.o”
“{ObjApp}TBox.cp.o”ƒ 
 “{SrcApp}TBox.cp” 
 “{SrcApp}TEDrag.MAMake” 
  {MacAppIntf} 
  {BuildingBlocksIntf}
 {MAEcho} {EchoOptions} “Compiling:     TBox.cp”
 {MACPlus} 
 {CPlusOptions} 
 -s TBox 
 -i “{SrcApp}” 
 -i “{MACIncludes}” 
 -o “{ObjApp}TBox.cp.o” 
 “{SrcApp}TBox.cp”
OtherRsrcFiles = 
 “{MAObj}Printing.rsrc” 
 “TEOther.rsrc”

 
AAPL
$111.78
Apple Inc.
-0.87
MSFT
$47.66
Microsoft Corpora
+0.14
GOOG
$516.35
Google Inc.
+5.25

MacTech Search:
Community Search:

Software Updates via MacUpdate

calibre 2.13 - Complete e-library manage...
Calibre is a complete e-book library manager. Organize your collection, convert your books to multiple formats, and sync with all of your devices. Let Calibre be your multi-tasking digital librarian... Read more
Mellel 3.3.7 - Powerful word processor w...
Mellel is the leading word processor for OS X and has been widely considered the industry standard since its inception. Mellel focuses on writers and scholars for technical writing and multilingual... Read more
ScreenFlow 5.0.1 - Create screen recordi...
Save 10% with the exclusive MacUpdate coupon code: AFMacUpdate10 Buy now! ScreenFlow is powerful, easy-to-use screencasting software for the Mac. With ScreenFlow you can record the contents of your... Read more
Simon 4.0 - Monitor changes and crashes...
Simon monitors websites and alerts you of crashes and changes. Select pages to monitor, choose your alert options, and customize your settings. Simon does the rest. Keep a watchful eye on your... Read more
BBEdit 11.0.2 - Powerful text and HTML e...
BBEdit is the leading professional HTML and text editor for the Mac. Specifically crafted in response to the needs of Web authors and software developers, this award-winning product provides a... Read more
ExpanDrive 4.2.1 - Access cloud storage...
ExpanDrive builds cloud storage in every application, acts just like a USB drive plugged into your Mac. With ExpanDrive, you can securely access any remote file server directly from the Finder or... Read more
Adobe After Effects CC 2014 13.2 - Creat...
After Effects CC 2014 is available as part of Adobe Creative Cloud for as little as $19.99/month (or $9.99/month if you're a previous After Effects customer). After Effects CS6 is still available... Read more
Evernote 6.0.5 - Create searchable notes...
Evernote allows you to easily capture information in any environment using whatever device or platform you find most convenient, and makes this information accessible and searchable at anytime, from... Read more
Command-C 1.1.7 - Clipboard sharing tool...
Command-C is a revolutionary app which makes easy to share your clipboard between iOS and OS X using your local WiFi network, even if the app is not currently opened. Copy anything (text, pictures,... Read more
Tidy Up 4.0.2 - Find duplicate files and...
Tidy Up is a complete duplicate finder and disk-tidiness utility. With Tidy Up you can search for duplicate files and packages by the owner application, content, type, creator, extension, time... Read more

Latest Forum Discussions

See All

Make your own Tribez Figures (and More)...
Make your own Tribez Figures (and More) with Toyze Posted by Jessica Fisher on December 19th, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
So Many Holiday iOS Sales Oh My Goodness...
The holiday season is in full-swing, which means a whole lot of iOS apps and games are going on sale. A bunch already have, in fact. Naturally this means we’re putting together a hand-picked list of the best discounts and sales we can find in order... | Read more »
It’s Bird vs. Bird in the New PvP Mode f...
It’s Bird vs. Bird in the New PvP Mode for Angry Birds Epic Posted by Jessica Fisher on December 19th, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Telltale Games and Mojang Announce Minec...
Telltale Games and Mojang Announce Minecraft: Story Mode – A Telltale Games Series Posted by Jessica Fisher on December 19th, 2014 [ permalink ] | Read more »
WarChest and Splash Damage Annouce Their...
WarChest and Splash Damage Annouce Their New Game: Tempo Posted by Jessica Fisher on December 19th, 2014 [ permalink ] WarChest Ltd and Splash Damage Ltd are teaming up again to work | Read more »
BulkyPix Celebrates its 6th Anniversary...
BulkyPix Celebrates its 6th Anniversary with a Bunch of Free Games Posted by Jessica Fisher on December 19th, 2014 [ permalink ] BulkyPix has | Read more »
Indulge in Japanese cuisine in Cooking F...
Indulge in Japanese cuisine in Cooking Fever’s new sushi-themed update Posted by Simon Reed on December 19th, 2014 [ permalink ] Lithuanian developer Nordcurrent has yet again updated its restaurant simulat | Read more »
Badland Daydream Level Pack Arrives to C...
Badland Daydream Level Pack Arrives to Celebrate 20 Million Downloads Posted by Ellis Spice on December 19th, 2014 [ permalink ] | Read more »
Far Cry 4, Assassin’s Creed Unity, Desti...
Far Cry 4, Assassin’s Creed Unity, Destiny, and Beyond – AppSpy Takes a Look at AAA Companion Apps Posted by Rob Rich on December 19th, 2014 [ permalink ] These day | Read more »
A Bunch of Halfbrick Games Are Going Fre...
A Bunch of Halfbrick Games Are Going Free for the Holidays Posted by Ellis Spice on December 19th, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »

Price Scanner via MacPrices.net

The Apple Store offering free next-day shippi...
The Apple Store is now offering free next-day shipping on all in stock items if ordered before 12/23/14 at 10:00am PT. Local store pickup is also available within an hour of ordering for any in stock... Read more
It’s 1992 Again At Sony Pictures, Except For...
Techcrunch’s John Biggs interviewed a Sony Pictures Entertainment (SPE) employee, who quite understandably wished to remain anonymous, regarding post-hack conditions in SPE’s L.A office, explaining “... Read more
Holiday sales this weekend: MacBook Pros for...
 B&H Photo has new MacBook Pros on sale for up to $300 off MSRP as part of their Holiday pricing. Shipping is free, and B&H charges NY sales tax only: - 15″ 2.2GHz Retina MacBook Pro: $1699... Read more
Holiday sales this weekend: MacBook Airs for...
B&H Photo has 2014 MacBook Airs on sale for up to $120 off MSRP, for a limited time, for the Thanksgiving/Christmas Holiday shopping season. Shipping is free, and B&H charges NY sales tax... Read more
Holiday sales this weekend: iMacs for up to $...
B&H Photo has 21″ and 27″ iMacs on sale for up to $200 off MSRP including free shipping plus NY sales tax only. B&H will also include a free copy of Parallels Desktop software: - 21″ 1.4GHz... Read more
Holiday sales this weekend: Mac minis availab...
B&H Photo has new 2014 Mac minis on sale for up to $80 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 1.4GHz Mac mini: $459 $40 off MSRP - 2.6GHz Mac mini: $629 $70 off MSRP... Read more
Holiday sales this weekend: Mac Pros for up t...
B&H Photo has Mac Pros on sale for up to $500 off MSRP. Shipping is free, and B&H charges sales tax in NY only: - 3.7GHz 4-core Mac Pro: $2599, $400 off MSRP - 3.5GHz 6-core Mac Pro: $3499, $... Read more
Save up to $400 on MacBooks with Apple Certif...
The Apple Store has Apple Certified Refurbished 2014 MacBook Pros and MacBook Airs available for up to $400 off the cost of new models. An Apple one-year warranty is included with each model, and... Read more
Save up to $300 on Macs, $30 on iPads with Ap...
Purchase a new Mac or iPad at The Apple Store for Education and take up to $300 off MSRP. All teachers, students, and staff of any educational institution qualify for the discount. Shipping is free,... Read more
iOS and Android OS Targeted by Man-in-the-Mid...
Cloud services security provider Akamai Technologies, Inc. has released, through the company’s Prolexic Security Engineering & Research Team (PLXsert), a new cybersecurity threat advisory. The... Read more

Jobs Board

Project Manager, *Apple* Financial Services...
**Job Summary** Apple Financial Services (AFS) offers consumers, businesses and educational institutions ways to finance Apple purchases. We work with national and Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Retail - Multiple Positions (US) - A...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.