Introduction
This library lets you manipulate graphic objects in your app at runtime.
Background
Sometime ago, I read that someone had asked for a way to drag items over a panel. Since I had the same problem (all began with the designer of MyNeoReport project) I tried to solve this in a generic way, so that the system could be used in different applications without efforts.
AGE supports items dragging, snap-to-grid, multiselection, layers and much more.
AGE is growing fast; if I were you I would keep an eye on this project.
Principal Subjects
GraphicItem
: The item to be drawnPainter
: The class that does the "dirty work" of paintingGraphicDocument
: The class that collects all the items to be drawn on a single surfaceCanvas
: The control that shows the drawing
Why This Set of Class?
Q: Why do I need an RendererBase
and why don't I put the Render()
method directly to the GraphicItem
class?
A: Because I need more abstraction.
In this way I separate the logical item from the actor of the rendering.
I can virtually have the same renderer for different items or I can choose a different renderer for a single item.
Q: Why is the GraphicDocument
a separate class from Canvas
? I could add all the items to draw directly to the Canvas
.
A: Same reason of the first question: the GraphicDocument
is the logical items aggregation, it is the document, the canvas
is the surface on which the document is drawn.
And again, in this way, I could have the same document open on more canvas.
Ok, Let's Start... How Does It Work?
Q: How can I make my own graphic document?
A: Ok, let's define a complete new custom document:
class CustomDocument : GraphicDocument
{
}
class Ellipse : GraphicItem
{
Color _foreColor = Color.Blue;
public Ellipse()
{
Painter = new EllipsePainter();
}
public Color ForeColor
{
get{ return _foreColor; }
set{ _foreColor = value; }
}
}
class EllipsePainter : Painter
{
protected override void Paint(Graphics g)
{
Ellipse ellipse = (Ellipse)Item;
Pen pen = new Pen(ellipse.ForeColor);
g.DrawEllipse(pen, Item.Bounds);
pen.Dispose();
}
}
...
canvas1.Document = new CustomDocument();
canvas1.Document.AddItem(new Ellipse());
From release 1.4.0.0, you can also use ScriptAge to define your custom graphic item at runtime:
ScriptedItem triangle = new ScriptedItem();
triangle.Script = "stroke: Polygon\n",
"pen: #7070ff, 2!\n",
"brush: gradient, #0000ff, #000000ff, (0; 0.5) (1; 1)\n",
"points: (0; 0.5) (1; 0.0) (1; 1)\n"
See the References section below for more details.
Limits in Items Drawing
How Can You Contribute?
If you think this article and the project published are interesting and/or useful, you can help me maintain it in many ways:
- Giving new ideas
- Notifying/fixing bugs
- Implementing new features
- Diffusing the project
- Putting a credit to this project in your application's About Box
- Voting for this article
- Visiting my Web site and its forum
- Visiting my Web site and making a little contribution (this would be a great incentive)
Credits
Thanks to Itai Bar-Haim for the help and enhancements provided.
Wish List
- [1.5.0.0] Zoom (Thanks to Itai Bar-Haim)
- [1.4.0.0 D] Porting to Linux+Mono
- [1.4.0.0 B]
ItemEnter
/ItemLeave
events - [1.3.0.0] Ability to load an
items
library - [1.3.0.0]
GraphicItem [Browsable(false)]Min/MaxSize
- [1.3.0.0]
SelectionPainter
to customize the rendering of the selection "border" of selected items - [1.3.0.0]
LoadFrom()
and SaveTo()
working on Stream
, so you can include the document as an assembly resource - [1.2.0.0] Layers
- [1.1.0.0] A good serialization way to save graphic documents
- [1.1.0.0] Ability to save the drawing as an image file
- [1.1.0.0] Toolbar Icon
- Ability to print the drawing
- Undo/Redo
- Clipboard Copy/Past of selected items
- Management of physical unit measures (cm, mm, meters, inches...) on screen and on other devices such as a printer
- ... Anything else?
I need some help... any suggestions?
References
History
For any questions or suggestions, please go to my Web site forum.
1.5.0.0
I'm sorry, this release is not 100% compatible with 1.4.0.0 C but, you should not have problems with it. I changed some property names, so I chose to change the version number, and you need to recompile applications that use AGE engine.
If you have some documents to be loaded, you must edit them with Notepad and replace the properties that were renamed (listed below).
- Added:
GraphicItem.RotationCenter
, GraphicItem.RotationCenterRelativeTo
that let you define the center of the rotation angleStroke.RotationCenter
, with ScriptAGE you can define a rotation point for each single strokeCanvas QueryCursor
event that lets you know about the cursor state and lets you set your custom cursor- Image Stroke
- Text Scripted Stroke beta (not fully working yet)
Theme
and DefaultTheme
classes that let you define the canvas appearance (Thanks to Itai Bar-Haim)Canvas.Zoom
property (Thanks to Itai Bar-Haim)- Drag handlers on each side of selected items (Thanks to Itai Bar-Haim)
- Fixed:
Canvas.Cursor
is now readonly and reflects the cursor state at runtime- Drag is only allowed with left mouse button (right and center buttons can be used for other purposes)
GraphicItem.Angle
were renamed in GraphicItem.RotationAngle
Stroke.Angle
were renamed in Stroke.RotationAngle
Canvas.GridSize
was renamed to Canvas.SnapGridSize
to avoid conflicts with the Visual Studio designer GridSize
property- ScriptAGE fixed for stroke and item properties
- A lot of other bugs
- Tested on Linux Ubuntu 7.4 + Mono 1.2.3.1: the engine works well, the designer needs some workaround since Mono does not completely support the
TreeView
(not implemented TreeView.Sort()
, TreeView.NodeMouseDoubleClick
event, TreeView.NodeMouseClick()
event)
1.4.0.0 Release C
In this release, I enhanced ScriptAge again.
ScriptAge is 100% compatible with the 1.4.0.0 release.
- Now ScriptAge can define strokes formed by multiple figures
- This lets you make a stroke formed by curves and lines together
- Added
path
, radial
, elliptic
brush types - Brushes now can have more than 2 colors
- Scriptage is now extensible: you can define your own
PaintStroke
class - Your custom stroke can define your accepted tokens overriding the
PaintStroke.ParseToken()
method - Added the
PathStroke
class
1.4.0.0 Release B
From now, I'll mark the AGE engine with the AssemblyDescriptionAttribute
to indicate the sub-release. This is because from 1.4.0.0, I signed the assembly with a strong name and I can no longer modify the release number for compatibility reasons.
In this release, I enhanced ScriptAge (see the References section).
ScriptAge is 100% compatible with the 1.4.0.0 release.
- Now ScriptAge supports comments, image token, multiline tokens, and more
- Some minor ScriptAge and
Canvas
fixes - Added
Canvas ItemMouseEnter
and ItemMouseExit
events - Fixed a bug with the Drag & Drop of controls on the
Canvas
at design-time
1.4.0.0
This release let me add an heavy improvement to the flexibility of this library allowing you to define an item directly at runtime.
- Added
ScriptedItem
class that lets you define the graphic with a little script - A bunch of code clean up
1.3.0.0
This time, the major change is the possibility to write custom items into separate libraries that can be loaded by the document at runtime.
- Added:
virtual GraphicItem.PointIsOverMe()
that lets you define if a point lies over the itemSize GraphicItem.MinSize
that lets you define the minimum size of an itemclass SelectionPainter
and GraphicItem.SelectionPainter
that lets you customize the selection border of your itemvirtual Document.LoadLibrary()
that lets you import GraphicItems
from external DLLsGraphicLayer Canvas.ActiveLayer
bool Canvas.AllowUserEditItems
and bool Canvas.AllowUserScrollCanvas
that lets you decide if the user can manipulate canvas content
and howPainter.GetPoint()
, Painter.GetSize()
, Painter.FlipPoint()
and Painter.FlipRectangle()
Painter.OnItemBoundsChanged()
- Something else that I don't remember
- The test project starts becoming a real designer
1.2.0.0
This release focuses on layers feature. It was a real challenge and it is still in beta (It works! I'm thinking of a more OOP solution).
- Added
Document.Groups
that define item groups and the wrapper GraphicDocument.Layers
- Removed the
ContextMenuStrip
from canvas
because is not a flexible solution for the applications that implement canvas
and it is not supported by Mono Canvas.OffsetX
and Canvas.OffsetY
are now Point Canvas.Offset
RendererBase
was renamed in Painter
, so it is more similar to the framework naming- Usual fixes and minor changes
1.1.0.0
This release focuses on the ability of saving the document on disk, but there were dozens of collateral enhancement on this:
- I did a big review of class infrastructure. Now I introduced these generic base classes:
This lets you derive what kind of document you want and lets you save it to disk without additional code.
GraphicDocument
now inherits from Document
and GraphicItem
inherits from DocumentItem
- Serialization is done by some classes that I won't describe in this article, also because they are not complete and may change soon
- Enhanced and fixed cursor and the selection way on
canvas
- Improved refresh speed
- Added virtual methods to let you decide to accept or cancel an action on an item or on the document:
Document.OnAddingToDocument(DocumentActionEventArgs e)
Document.OnRemovingFromDocument(DocumentActionEventArgs e)
Document.OnAddedToDocument(DocumentActionEventArgs e)
Document.OnRemovedFromDocument(DocumentActionEventArgs e)
DocumentItem.OnAddingToDocument(DocumentActionEventArgs e)
DocumentItem.OnAddedToDocument(DocumentActionEventArgs e)
DocumentItem.OnRemovingFromDocument(DocumentActionEventArgs e)
DocumentItem.OnRemovedFromDocument(DocumentActionEventArgs e)
GraphicDocument.SaveImage(string fileName, ImageFormat format)
GraphicDocument.GetBounds()
GraphicDocument.GraphicItems
Document.SaveTo(string fileName)
Document.LoadFrom(string fileName)
Document.OnLoadingDocument()
Document.OnSavingDocument()
Document.OnDocumentLoaded()
Document.OnDocumentSaved()
- Removed the
Renderer.RenderType enum
: now it is the Canvas
that decides how and what to render - Added properties:
Canvas.DrawInvisibleItems
Canvas.DrawDocumentBounds
Document.Items
is now a GraphicItemCollection
Canvas.SelectedItems
is now a GraphicItemCollection
Canvas.ItemMouseDoubleClick
event is now Canvas.ItemDoubleClick
- Added
Canvas.ItemClick
event - Various minor modifications and fixes that I don't remember
1.0.0.0
- This is the first public release