Suppose I have PathGeometry, consisting of lines, like this
(the rectangle == panel, for example Grid):
I want to fill them to the bottom of the panel, like this:
The quick and not very good solution I see is to create additional curve with 2 additional points in the bottom and use it for filling.
Is there some better way to solve the task?
Something like this (pseudocode):
<Path Data=... FillStyle = "ToTheBottom" Fill="Blue"/>
There is no standard way of doing this; there is no Fill like this defined in WPF.
You could put two path geometries on top of each other. The bottom one would have a stroke thickness of 0 and has 2 extra points (those on the lower edge of the rectangle)
The second one the top would simply be the geometry you have now.
If you need to draw a lot of these you might create a custom control that does this for you.
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!
First time working on a GUI project.. and first time doing work on Windows so apologies in advance if this is a really noob question.
I'm taking baby steps into windows programming starting with vb.net WPF. Working in Visual Studio Express 2012.
I'm trying to work out how I can scale all the elements in a window with the window itself.
So for example, I'd create a window, say 1280x720, and place some images in the window. Say one at the top and one in the corner. (this is a basic media based application)
When I resize that window, I want the entire window to scale with it, so image 1 & 2 will get larger if the window gets larger, however this has to happen proportionally so that if I make the window a lot bigger in one direction one image can't overlap the other. Imagine the window is an image and I'm trying to resize it. (The overlap thing is the closest I've gotten to getting this working in my current attempts).
The layout in produciton will be more complex, comprising of mediaelements (video), images, text etc and all must scale accordingly.
This isn't something the user interacts with and so there are no form elements etc, and so I don't need form fields etc to stay the same size throughout scaling. I just need everything to scale like I'm scaling a picture. If for example I displayed this 1280x720 (16:9) layout on a 1920x1080 screen, maximised it should look identical only larger.
Hoping someone can point me in the right direction with this.
What I've tried so far- the few articles I did find on google relating to this (I may well be searching the wrong things) lead me to put all the elements in a viewbox, this lead to the overlap I mentioned earlier.
Ideas ?
I think you could use ViewBox container. The basic idea is as follows: ViewBox scales its content just as if it was an image scaled. This seems to be the closest result to what you've described in your question. Just put a Grid with absolutely-sized columns and rows into the ViewBox and set its Stretch to be Uniform:
<Viewbox Stretch="Uniform">
<Grid>
<..>Your controls, MediaElements, etc
<Grid>
</Viewbox>
You could also combine it (or entirely replace) with (e.g.) Grid Container : it gives you an ability to specify cell width and size usign star-syntax which is similair to html's percent syntax.
Another way is to use the DockPanel.
All-in-all there are plenty ways to achieve something similair and the way to go largely depends on the nuances of your particulair requirements.
Have a look at This tutorial to see a good overview of WPF containers and how to use them.
I want to implement a rather complex CurveEditor that has to support the usual requirements like:
freely scalable and moveable axis
different interpolation types per curve point (Linear, Cubic, Spline)
Tangents (joined and broken)
Selecting one or several points to edit (move, scale, delete) via Fence or Click
Only show handles and highlights for selected curve points
I don't want to manipulate actual WPF curves but an existing model with key/value/tangents sets and sample the precise shape of the curve from our implementation.
I already gathered some experience on implementing custom UserControls and Templates. But I want to make sure, I don't miss any apparent solution. I planned to have this general XAML-tree:
CurveEditor - Window holding all content
MainThumb : Enable dragging and scaling the editor range
XAxis : UserControl rending some scale on the left side
YAxis : UserControl rending some scale on the bottom
Curves : Canvas holding the curves
Curve : UserControl for a single curve
CurveName - Label of the curve
CurveLine - DrawingVisual that will render the actual curve by sampling the internal implementation of the spline function.
CurveEditPoints - Canvas that holds all edit points
CurveEditPoint - UserControl for a single edit point
LeftTangent - UserControl for the left tangent handle
LeftTangentThumb - For modifying the handle
RightTangent - UserControl for the right tangent handle
RightTangentThumb - For modifying the handle
CurvePointCenter - Visualisation of the actual point, select state and interpolation type.
CurvePointThumb - Thumb to select and drag point around
I know, this is quite a complex question and I am not asking for an actual implementation. I am interested in the following questions:
Can you recommend any tutorials or books that might help me (I already got Illustrated WPF, WPF Control Development Unleashed, and a couple of other)
Should minor elements like the Tangents be individual UserControls?
What container is best suited for hosting the individual "Curves", "EditPoints" and "Tangents". Right now, I use Canvas and Canvas.SetLeft/SetTop to position the children, but that feels "strange".
Should I use "Shapes" like Path or DrawingVisual-Classes to implement actual representation. Path is straight forward, but I am concerned about performance with hundreds of CurvePoints.
Should I use Transforms to rotate the tangents or is just fine to do some triangulation math in the code behind files?
Does the structure roughly make sense, or do you suggest a completely different approach?
you seem to have the right tools at hand, WPF Unleashed is excellent, but I guess you have that one already.
make individual UserControls in one of these cases:
you are using the same xaml all over the place (DRY)
you xaml file gets too big (get some components out)
you need to inherit from some class
this depends on how much codebehind you want.
you can, as you suggested in your comment, use an ItemsControl as a container for wherever you need selection between multiple items. so this could also be done on the level of Curves, not just on the level of points on the curve. Depending on how you want to handle drawing of the actual lines and curves you can even have an ItemsControl for those. (on a side note: you will not have virtualization out of the box though, as your items won't have a constant height)
Path is OK with hundreds of CurvePoints. If you have 10.000, I'd say you could get problems.
can't imagine how a transform should be used here, maybe inside an Adorner.
your structure looks good. you will be able to implement all of this. I will suggest though how I would do it:
first of all use MVVM.
CurveEditor
ListBox(Panel=Canvas)(ItemsSource=Curves)(ItemTemplate=CurveControl)
CurveControl
Canvas(Background=Transparent) <= I'm not sure if standard is white, but you don't want to overlap other Curves...
CurveName
ListBox(Panel=Canvas(Background=Transparent))(ItemsSource=CurveParts)
ListBox(Panel=Canvas(Background=Transparent))(ItemsSource=CurvePoints)(ItemTemplate=>EditPointControl)
EditPointControl
Canvas
Thumb(Template = Ellipse) (Name=CenterHandle) (with some Visualstates for Selection and hiding of Tangents)
Thumb(Template = Ellipse) (Name=LeftHandle)
Thumb(Template = Ellipse) (Name=RightHandle)
Line (Binding X/Y to Centerpoint and LeftHandlePoint)
Line (Binding X/Y to Centerpoint and RightHandlePoint)
I have stated to set ItemTemplate for the ListBox. You can however style the listbox however you want (I think the standard style includes a border, you might want to remove that or set bordersize=0) and set instead of ItemTemplate the ItemContainerStyle and bind to IsSelected so you have control over IsSelected from your ViewModel (look here for what I mean).
So the viewmodel looks like this:
- CurveEditorViewModel
- ObservableCollection<CurveViewModel> Curves
- CurveViewModel
- string Label
- (Point LabelPlacement)
- bool IsSelected
- ObservableCollection<CurvePointViewModel> CurvePoints
- ObservableCollection<CurvePartViewModel> CurveParts
- CurvePointViewModel
- Point Position
- bool IsSelected
- Point LeftHandle
- Point RightHandle
- CurvePartViewModel
- CurvePointViewModel StartPoint
- CurvePointViewModel EndPoint
- Path CurvePath
in here you can subscribe to CurvePointViewModel's PropertyChanged and recalculate the Path you're exposing.
I'd probably improve on it as I go but that'd be my first guess.
There are some details you might want to watch out for. eg: the style for the thumbs might be a visible circle in the middle and an invisible bigger one around that with background=transparent. that way you can have your visible circle small, but have the user use the tumb in an area around the small circle.
EDIT:
here is an Example for the Thumb:
<Thumb Width="8" Height="8" Cursor="Hand" Margin="-4">
<Thumb.Template>
<ControlTemplate TargetType="Thumb">
<Grid>
<Ellipse Fill="Transparent" Margin="-6"/>
<Ellipse Stroke="Red" StrokeThickness="2"/>
</Grid>
</ControlTemplate>
</Thumb.Template>
</Thumb>
as you want to position this at a specific point on a canvas setting the Margin to minus half the width and height will place the center of the circle on that point. Furthermore, having that inner ellipse with a transparent fill and Margin of -6 you will get a 6px bigger radius around the inner (smaller) circle where you can drag the thumb.
In a simple code-only WPF application I'm writing, I would like to have a custom Canvas.
I've found questions similar to this one here in StackOverflow, but couldn't find exactly this one, nor a simple way to adapt another answer to my specific problem (please note that I have not much experience in WPF).
In my canvas, I'd like it to have the following properties:
the point (0, 0) is on the center of the Canvas;
the x-axis points to the right;
the y-axis points to the top;
the point (1, 0) is about 1 inch to the right of the origin; and
in every event, the position of the mouse is given in the coordinate system defined above.
In this answer, Ray Burns propose a very simple solution to my first 3 points. It is trivial to modify that code so that it deals with my point number 4 as well (change 1 and -1 in the RenderTransform to other constants).
However, that very simple and excellent solution for many problems is based on setting width and height to 0, and centering the canvas on its container. Therefore, there's no canvas to capture events like a click, so this solution won't handle my fifth property.
What's the easiest way to achieve this? Inherit from Panel and do everything by hand? Inherit from Canvas, intercept every event and modify the coordinates?
Put Canvas inside a Border. Border has mouse events. Another case is to place Border on the top of the Canvas.
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.