So there's this tutorial about creating a diagram in WPF.
http://www.codeproject.com/Articles/24681/WPF-Diagram-Designer-Part
I've read it, and still studying it to understand it completely.
At the end of this tutorial, you can basically add shapes, move/rotate/scale them, and since they are created in a vector form, they are keeping their resolutions, there are also connectors that can connect each shape with another.
My goal, since I need to create a simulator which shows how internet protocols are delivered, is to create a divided diagram in which Side A communicates with Side B. it could read an automata and simulate the transitions in the diagram.
I'm thinking of how to deliever this, and since I don't have a lot of knowledge in WPF, I wonder in which way should I implement it.
Should I create 2 different Canvases? or maybe dividing 1 canvas with two sides?
The main issue I'm dealing with, is that when a shape is being dragged to the end margin of the window, then the window allow me to slide it so I can see the rest of the field, this is being done by increasing the size of the Canvas, as seen in the Tutorial Part 1.
However, if my canvas is divided by two, and there's a border in the middle, how can I create two sliders for each of the sides?
I was wondering if you can give me any tips about how approaching this idea, since my knowledge in WPF is still very limited.
Here is my point of view, but it would be very useful if you would provide a more/less final sketch of your app. I recommend using Telerik AppMock but paint will also suffice ;).
From what I have understood you should need 3 canvases.
1-st is canvas on the left.
2-nd is canvas on the right.
3-rd is on top of both canvases.
When you want to drag an element, you must set opacity of the clicked element to be a bit transparent and leave it on its place(1st canvas), add copy of dragged element in to the 3rd canvas. When you do leftmousebuttonup(drop dragged item), you have to check where was it dropped and if it was droppend on the 2nd canvas you add it to this canvas. To position element on the canvas you can use Canvas.SetLeft and accordingly SetRight method.
You can put 1st and 2nd canvases into Grid. Even if Canvases will be bigger if Grid, view will be cut only to the size of the Grid.
Moreover, to allow canvases manipulation, add there (to the Grid) a scrollviewer which will Translate Transform the canvases given to their sizes.
Later, try to use MVVM pattern to fill your Canvases with data.
I would also suggest an ObservableColletion of drawable (you can use FrameworkElement as base class) and draggable objects. Different for every Canvas.
Good luck!
Related
I am working on a form designer application in wpf. A functionality to show a alignment rular at runtime as in WPF designtime has to implement. Please suggest me the approach. Or anyone who done it before?
I'm drawing a lines with the respective element (Control). As i will have four possible controls to which we have to draw measurement line.
Step 1. I have all children of controls with its location in a list, which i have prepared on drawing controls at run-time at Mouse move event.
Step 2: I calculate the closest cords difference with respective controls. and drawn line for for that points.
I am new to silver light and would like to understand a bit more from the pros. Let me tell you what I am trying to do. I am into photography and my goal is to create a web site that allows users to view their images and be able to rotate, zoom, crop, special effect etc. I have developed the web site that allows users to order pictures but now I want to start working on the actual picture/image manipulation. So for testing i put a canvas and a rectangle( with an image). Placed a slider and was able to link the slider to the rectangle. As i increase the slider the image gets larger. But I was kind of hoping as the image gets larger it does not surpass the boundries of the canvas. I assumed that is what it means by being a child of a canvas. Am i mistaken? If so how do you suggest me doing this? Remember I am very new to this and may be going about this very wrong.
Thanks!
Your are right. In Silverlight (like in WPF, WinForms etc.) gui-elements form a hierarchy of elements wherein controls can act either as parents or as children.
The reason why your rectangle surpasses the boundaries of it's container lies in the way controls are getting aligned. This depends on what kind of container you want to place your child into.
In a canvas for example you position the children with absolute measurements (left, top, height, width). In a self-organizing container like the StackPanel you choose an horizontal alignment (Left, HCenter, HStretch, Right) or a vertical alignment (Top, VCenter, VStretch, Bottom) which determines the childs behavior when you place it inside the parent. Furthermore you can specify the dimension of the child (Width, Height) and an optional margin which determines the gap between the Top, Right, Bottom and Left bound of your child to its enclosing parent.
But what ever container you choose it's inherent to it that you can let its children surpass its boundaries e.g. with a margin that is negative or greater than the container boundaries or simply by an child that is bigger in dimension that its container as you described the situation with your rectangle.
In your case I would consider working with the idea of clipping. Clipping simply means to
(1) define an geometrical area (in Silverlight and WPF it is a Path object) which lies over some graphical context (some section of your ui or your control etc).
(2) what lies inside the boundaries of this clipping area remains visible and everything else remains invisible.
So you can think of a clipping area as a window onto your screen which you use to look through.
When you are using Microsoft Blend this is easy to realize:
(1) Just use a geometrical shape like a Rectangle, a Circle or a custom Path.
(2) Place it somewhere upon your UI
(3) Right-click the shape, select "Path" and then "Make clipping Path"
(4) and voulà, you've just defined a clipping area which you can modify as you are used to modify controls.
Hope this gave you an idea how to deal with your problem.
cheers.
Being new to silverlight I'm struggling to 'get going' with the following.
Basically I wish to create some form of grid like control (custom or user?).
The idea is similar to that of a planner. Along the top are times (set intervals). Downwards are subjects. Then over the grid like background rectangles (or something) indicate when the subject is planned for.
The actual design of the above is not the issue. i.e. a grid with ractangles overlaid. But my issue is I wish this grid to be scrolled up and down (with bounds fixing the top and bottom when the subject lines start and end). And also the grid to be scrolled left and right (with bounds fixing how far left and right it can scroll, current time & 3 days into future).
Based on the above needs, I don't wish to create a control which is very large, and just dragged into view (unless this is the only way?) but instead show the grid at a current time and when dragged dynamically load the next few hours worth of content, possibly with a few hours buffer.
The appearance I am seeking is it looking like it is one massive control, but truely its not, its dynamic.
Does this make sense? Am I worrying about nothing? Should I create a massive grid well into the future and then just handle the load of data dynamically over the top? Its just my concern if I want a grid 3 month into the future this would be massive and a waste of memory.
I'm struggling to find examples on the net, but feel this maybe to do with me not knowing what to search for. This isn't about getting a detailed answer and someone doing it for me, but instead about guidance pointing me in the right direction.
Many thanks
About the up-down scroll: you can simply put a grid containing your data in a ScrollViewer control - this will handle all the scrolling for you. Another solution would be using a listbox control - this is better if you use MVVM. You can bind it to a data source and set as data template a custom control.
For the left-right scroll. I'm thinking you could use gestures for this. Like - catch left-to-right and right-to-left flicks and change the data in your grid / listbox according to the gesture's direction. You could also place two buttons at the top of the grid to handle scrolling from one day to the other (just like in the calendar controls: gestures + buttons).
I'm sort-of just nit picking here, but maybe there's a simple solution which will save me some time.
When I'm drawing my Winforms GUI in the designer, controls snap to certain points. I can align the baseline of the text of one control to that of another, I can align the left and/or top of one control to another, etc. This is all great.
What's great too, is that the controls snap to other controls spaced with their margins. This means that if I'm making a vertical array of TextBoxes, then I can have them equidistant in my GUI - it looks less messy.
However not everything snaps correctly, or at all. Say I have put in my TextBoxes and now I wish to reduce the width of my form so that there is no white space between the edges of the TextBoxes and the edge of the form. Additionally, I want the distance between the edge of the TextBoxes and the edge of the Form to be the same on the left as it is on the right. If I drag the right edge of the form to the left, towards the TextBoxes it will not snap. I'm left with either calculations to work out what the width should be, or a juggling act to gradually reduce the width until the TextBox is snapping to both the left of the right.
I'm not saying this process is particularly difficult or time consuming. It's just that if it were to snap, the whole process would be infinitely easier.
Is there a built-in option in VS2010, or perhaps an extension? Or maybe I'm just doing it wrong in the first place?
The snap lines in the designer work perfectly when moving or resizing any of the built-in controls. The only time that they don't work is when you are resizing the form itself.
I agree that it would be extremely convenient to have snap lines here, as well. I wish I knew of a way to enable this. But unfortunately, I don't believe that there is one.
The workarounds are either to calculate the proper size mathematically, or guess at resizing the form then check your work by dragging one of the controls (and using the snap lines that appear). I go through the same "juggling act" that you describe on an unfortunately regular basis.
Whenever a control needs to be positioned so that it "snaps" to a form edge I usually move (or resize) the controls to the correct size first, and then change the controls "Anchor" property of those controls to be anchored to the corresponding form edge (even if the form itself won't be allowed to resize).
That way whenever I resize the form, the controls position relative to that form remains the same, simply resizing or moving the control as required (depending on the Anchor property chosen).
I completely agree that the ability to "snap" the form to controls when resizing the form would be extremely useful, but its normally possible to work-around using the anchor property in this way - the times when its doesn't work (such as when a form consists entirely of a column of text-boxes is a fixed height), I'm afraid you need to resort to calculations, but I find that most of my dialogs are resizable.
I'm currently creating a MSPaint-like WPF-application and struggling with the implementation of a snappable grid.
The painting of the grid is no problem with a VisualBrush and a Rectangle but the problem is that these lines are then purely for looks and can't be easily changed (for example highlighted when the snapping to a specific line triggered).
My other idea was to have a 2 Canvas solution where 1 Canvas is used for the elements and one Canvas (who is positioned above the other) contains all the grid lines. However I have the feeling that this would mean quite a performance hit.
Are there any other possible ways to implement this kind of functionality?
Efficiency considerations of a two-panel approach vs DrawingContext
I have good news for you: You are wrong about the significant performance hit. Your two-canvas idea is nearly optimal, even if you use individual objects for the grid lines. This is because WPF uses retained-mode rendering: When you create the canvas, everything on it is serialized into a compact structure at native level. This only changes when you change the grid lines in some way, such as changing the grid spacing. At all other times the performance will be indistinguishable from the very fastest possible managed-code methods.
A slight performance increase could be had by using DrawingContext as Nicholas describes.
A simpler and more efficient solution
Perhaps a better way then drawing individual lines on the grid canvas is to use two tiled visual brushes (one horizontal, one vertical) to draw all unhilighted lines, then use Rectangle(s) added in code-behind to hilight the line(s) you are snapping to.
The main advantage of this technique is that your grid can be effectively infinite, so there is no need to calculate the right number of grid lines to draw and then update this every time the window resizes or the zoom changes. You also only have three UIElements involved, plus one more for each grid line that is currently hilighted. It also seems cleaner to me than tracking collections of grid lines.
The reason you want to use two visual brushes is that drawing is more efficient: The brush drawing the vertical lines is stretched to a huge distance (eg double.MaxValue/2) in the vertical direction so the GPU gets only one drawing call per vertical line, the same for the horizontal. Doing a two-way tiling is much less efficient.
Adorner layer
Since you asked about alternatives, another possibility is to use Adorner and AdornerLayer with any of the solutions above rather than stacking your canvas using eg a Grid or containing Canvas. For a Paint-like application this is nice because the adorner layer can be above your graphic layer(s) yet the adorners can still attach to individual items that are being displayed.
You might consider drawing your grid using the DrawingContext inside of OnRender. Drawing this way does not introduce new UIElements into the visual tree, which helps to keep performance up. In some ways, it is similar to what you are currently doing with the VisualBrush, which also does not create new UI elements per copy.
However, since you will actually be individually drawing each line instead of copying the look of a single line, you'll be able to highlight the grid line(s) that participate in snapping without changing the colors of those that do not.
If you are going to go down this route, make sure to have a look into GuidelineSets for positioning your guide lines (more details here), since you'll probably want to have your guide lines snap to the device's pixels so that they draw sharply.