Is there a way to know is certain FrameworkElement was rendered to the screen. For example. I have two rectangles, and one overlap other. But I'm not sure about "how much" one overlap other.
So I need to know is user will see both rectangles, or will see only one, or will see one fully and one partially?
It all depends on what kind of parent container it is, if both rectangles are inside StackPanel then they will not, you have to either make a custom container or use canvas as parent of these rectangles.
Then you can get LocalToScreen or such similar methods to get their absolute positions compared to screen or top parent window and find out whether they overlap or not.
Related
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!
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.
I'm trying to make an application which allows the user to draw shapes to the canvas. Once drawn, I would like for the user to be able to select, move, resize, basically manipulate the shapes in any which way.
I have done something similar in XNA and that was quite easy due to the fact that there was a draw loop. In Silverlight there is no such thing as far as I understand and I am having trouble figuring out how to manage the objects on the canvas. As in what is the best way to manage the canvas' children collection to ensure appropriate response of the UI to what the user does.
Most examples out there are pretty basic and do not go anywhere near this kind of thing. I would be grateful if somebody who has done this before could tell me how they approached the problem.
Thinking about it for a while I think I figured out how it works.
There is a draw loop for the canvas, which is the draw loop of the top level parent container which it lives on.
The difference with XNA I guess is that the collection of items to draw on the canvas doesn't need to be explicitly drawn, since the canvas takes care of drawing its children automatically.
So, what I need is some way to hold on to any object I add to the canvas' children... I can then update the objects drawing properties and the changes will be reflected in the canvas next time it refreshes.
I guess a dictionary of some sort in which to store the items I put in the list might be best...?
Not a finished answer yet, but I guess I understand half of it now.
I have a container whose size can change.
I will by dynamically creating instances of a user control and adding them to that container.
the size of the user control is fixed. what I want to do is, fit the most number of user controls in the container.
I think a good approach is to add the children horizontally until there is no more space to add another and then start another row.
Say, each row fits 3 children for a given width of the container. if it is expanded enough, it should automatically fit 4 children in a row.
Is there a container control (StackPanel Grid etc.) that I can use to host these user controls. What properties need to be changed.
On resizing the container, it should relocate the children so that the maximum children ae shown. Scrolling is okay as long as max are shown at any given time.
Is there a container that does this automatically? or should I manually create rows or panels or something and add n children to each - i.e., do it manually?
I think what you need is a WrapPanel.
There's a Panels Overview on the MSDN with a lot more information and links to specific types of Panel including the WrapPanel:
WrapPanel positions child elements in sequential position from left to right, breaking content to the next line at the edge of the containing box. Subsequent ordering happens sequentially from top to bottom or right to left, depending on the value of the Orientation property.
I think a good approach is to add the children horizontally until there is no more space to add another and then start another row.
This is exactly what a WrapPanel does.
A client has asked for a display to flick over like an airport display screen, ie each row flicks over when information changes.
I am not sure which is the best control to use, or the method of getting each row to transform one after the other.
any suggestions woul b gratfully accepted
John
Here's what I would do in general concept..
Make a regular panel of, say 50px high. (This is arbitrary but this panel just holds the size in place so the control doesn't shrink with its contents.)
Create a panel inside that one that will be the 'animated' panel.
When it's time for information to animate, create a storyboard that uses a transformation to "stretch" the height down to 0, change the content to the updated information, then tranform stretch the height back to 50px. This will create the illusion that the panel is flipping over.
If you make this a user control, then you could simply add however many "rows" you needed of this control to a StackPanel to make your screen.
The best way of representing this effect easily is to randomize the text during the change.
Patrick Long implemented this effect as a custom animation here