I'm trying to find the GTK equivalent of Control.Controls, which is something that is only available in System.Windows.Forms, same thing for ControlCollection.
So I was wondering if anyone knew the GTK equivalent to that, or if there's a solution to making something similar in GTK? Because those functions had features like add and remove, but I'm unable to find anything similar in that regard.
The code that I have with me right now that I wish to change, is this:
private void CreatePianoKeys()
{
// If piano keys have already been created.
if (keys != null)
{
// Remove and dispose of current piano keys.
foreach (PianoKey key in keys)
{
Controls.Remove(key);
key.Dispose();
}
}
keys = new PianoKey[HighNoteID - LowNoteID];
whiteKeyCount = 0;
for (int i = 0; i < keys.Length; i++)
{
keys[i] = new PianoKey(this);
keys[i].NoteID = i + LowNoteID;
if (KeyTypeTable[keys[i].NoteID] == KeyType.White)
{
whiteKeyCount++;
}
else
{
keys[i].NoteOffColor = Color.Black;
keys[i].BringToFront();
}
keys[i].NoteOnColor = NoteOnColor;
Controls.Add(keys[i]);
}
}
Because I'm currently trying to change the UI from WinForms to GTK, so it can work on Linux distributions.
Any help with this would be greatly appreciated! Thank you!
Yes, but just like in .NET, in GTK, only certain kinds of widgets ("Controls" in .NET-speak) can specify its children (like the ControlCollection in your example). These parent widgets are usually objects that derive from the Gtk.Container base class, which implements the Gtk.Buildable interface.
You can add children to any Container object by using its Add() or Remove() methods, just like you do with the ControlCollection object In C#. Since this is a piano, you could use a Gtk.Box (or a subclass of it), which is a container that shows its children widgets in a single row back-to-back if specified as horizontally-oriented. Since I don't know what sort of class your PianoKey is, I can't suggest a good alternative in GTK, but hopefully that helps.
Related
Can somebody provide an overview for use of the XamlBindingHelper class with examples? Specifically the GetDataTemplateComponent and SetDataTemplateComponent method.
In the official document, it says
This class is for use in code that is generated by the XAML compiler.
This tells me that I should be able to find some reference of it in code-generated classes (.g.cs) by x:Bind, given there's not a single thread on the Internet that explains what exactly it does.
So I created a test UWP project with a ListView, and inside its ItemTemplate I threw in some x:Bind with x:Phase. After I compiled the project, I found some of its methods used inside my MainPage.g.cs -
XamlBindingHelper.ConvertValue
public static void Set_Windows_UI_Xaml_Controls_ItemsControl_ItemsSource(global::Windows.UI.Xaml.Controls.ItemsControl obj, global::System.Object value, string targetNullValue)
{
if (value == null && targetNullValue != null)
{
value = (global::System.Object) global::Windows.UI.Xaml.Markup.XamlBindingHelper.ConvertValue(typeof(global::System.Object), targetNullValue);
}
obj.ItemsSource = value;
}
Apparently the XamlBindingHelper.ConvertValue method is for converting values. I knew this already, as I used it in one of my recent answers on SO.
XamlBindingHelper.SuspendRendering & XamlBindingHelper.ResumeRendering
public int ProcessBindings(global::Windows.UI.Xaml.Controls.ContainerContentChangingEventArgs args)
{
int nextPhase = -1;
switch(args.Phase)
{
case 0:
nextPhase = 1;
this.SetDataRoot(args.Item);
if (!removedDataContextHandler)
{
removedDataContextHandler = true;
((global::Windows.UI.Xaml.Controls.StackPanel)args.ItemContainer.ContentTemplateRoot).DataContextChanged -= this.DataContextChangedHandler;
}
this.initialized = true;
break;
case 1:
global::Windows.UI.Xaml.Markup.XamlBindingHelper.ResumeRendering(this.obj4);
nextPhase = -1;
break;
}
this.Update_((global::System.String) args.Item, 1 << (int)args.Phase);
return nextPhase;
}
public void ResetTemplate()
{
this.bindingsTracking.ReleaseAllListeners();
global::Windows.UI.Xaml.Markup.XamlBindingHelper.SuspendRendering(this.obj4);
}
XamlBindingHelper.SuspendRendering & XamlBindingHelper.ResumeRendering look very interesting. They seem to be the key functions to enable ListView/GridView's incremental item rendering which helps improve the overall panning/scrolling experience.
So apart from x:DeferLoadingStrategy and x:Load(Creators Update), they are something else that could be used to improve your app performance.
IDataTemplateComponent & IDataTemplateExtension
However, I couldn't find anything related to GetDataTemplateComponent and SetDataTemplateComponent. I even tried to manually set this attached property in XAML but the get method always returned null.
And here's the interesting bit. I later found this piece of code in the generated class.
case 2: // MainPage.xaml line 13
{
global::Windows.UI.Xaml.Controls.Grid element2 = (global::Windows.UI.Xaml.Controls.Grid)target;
MainPage_obj2_Bindings bindings = new MainPage_obj2_Bindings();
returnValue = bindings;
bindings.SetDataRoot(element2.DataContext);
element2.DataContextChanged += bindings.DataContextChangedHandler;
global::Windows.UI.Xaml.DataTemplate.SetExtensionInstance(element2, bindings);
}
break;
The method DataTemplate.SetExtensionInstance looks very similar to XamlBindingHelper.SetDataTemplateComponent. It takes element2 which is the root Grid inside the ItemTemplate of my ListView, and an IDataTemplateExtension; where the latter takes an element and an IDataTemplateComponent. If you have a look at their definitions, their functionalities are very similar, which makes me think if DataTemplate.SetExtensionInstance is the replacement of XamlBindingHelper.SetDataTemplateComponent? I'd love to know if otherwise.
Unlike IDataTemplateComponent, you can get an instance of the IDataTemplateExtension in your code -
var firstItemContainer = (ListViewItem)MyListView.ContainerFromIndex(0);
var rootGrid = (Grid)firstItemContainer?.ContentTemplateRoot;
var dataTemplateEx = DataTemplate.GetExtensionInstance(rootGrid);
In my case, the dataTemplateEx is an instance of another generated class called MainPage_obj2_Bindings, where you have access to methods like ResetTemplate and ProcessBindings.
I assume they could be helpful if you were to build your own custom list controls, but other than that I just can't see why you would ever need them.
So, I am doing this, wanting to be cool:
List<CheckButton> cbuttons = new List<CheckButton>(
new CheckButton[] {
cbShowAll,
cbShowApproved,
cbShowNew,
cbShowQC,
cbShowSent });
cbuttons.ForEach(b => b.LookAndFeel.UseDefaultLookAndFeel = false);
Is there a more cool way to do it?
EDIT:
There might be CheckButtons that won't be affected. There might be multiple property and/or method calls per group.
To make it applicable for many such controls like TextBox or CheckBox, create an extension method on the Form like so:
public static class FormExtensions
{
public static void ChangeAll<T>(this Form form, string propName, object value) where T : Control
{
foreach (Control c in form.Controls.OfType<T>())
{
PropertyInfo myPropInfo = typeof(T).GetProperty(propName);
if (myPropInfo != null)
{
myPropInfo.SetValue(c, value, null);
}
}
}
}
and we can call it:
this.ChangeAll<CheckBox>("Checked", false);
this.ChangeAll<Button>("Text", "DefaultButtonName");
this.ChangeAll<TextBox>("Text", "DefaultText");
where this is Form1 : Form
Unless that list is dynamic, doing it the “boring” way will be likely more efficient:
cbShowAll.LookAndFeel.UseDefaultLookAndFeel = false;
cbShowApproved.LookAndFeel.UseDefaultLookAndFeel = false;
cbShowNew.LookAndFeel.UseDefaultLookAndFeel = false;
cbShowQC.LookAndFeel.UseDefaultLookAndFeel = false;
cbShowSent.LookAndFeel.UseDefaultLookAndFeel = false;
Other than that, you could subclass the CheckButton and make that the default value too.
Also, in general “readable and possibly efficient” is much better than “cool and fancy”.
If you're performing some one-off initialization on a particular subset of controls (rather than all of them), then you could create an array containing that subset and then enumerate the array:
foreach (CheckButton button in
new[] { cbShowAll, cbShowApproved, cbShowNew, cbShowQC, cbShowSent })
{
button.LookAndFeel.UseDefaultLookAndFeel = false;
}
Using a loop allows you to avoid duplicate code (as in poke's answer).
Note: Eric Lippert wrote a blog post explaining why he prefers foreach over ForEach. Excerpt:
[Providing a ForEach extension method] lets you rewrite this perfectly clear code:
foreach (Foo foo in foos) { statement involving foo; }
into this code:
foos.ForEach((Foo foo) => { statement involving foo; });
which uses almost exactly the same characters in slightly different order. And yet the second version is harder to understand, harder to debug, and introduces closure semantics, thereby potentially changing object lifetimes in subtle ways.
Also, not all versions of the .NET Framework support List<T>.ForEach. For example, if you're writing a Windows Store app, you need to use foreach instead.
If you want to do that with all the CheckBoxes you have inside of a form or control, you don't need to hard code the array. If you're hard coding everything, then I agree with poke's answer.
However, you could be totally dynamic and if this is something you want to be reusing in many places, you could have a utility method (or something in a base form or control class that fires after the InitializeComponents() method).
If you want that, you could do something like this:
this.Controls.OfType<CheckBox>()
.ForEach(b => b.LookAndFeel.UseDefaultLookAndFeel = false);
If you don't want to do that with every CheckBox, you could create a subclass of those, and substitute that class name in the OfType generic declaration.
I've found similar answers to my question before, but not quite to what I'm trying to do...
In Visual Basic (last I used it, in 06/07) there was an "Index" property you could assign to multiple controls with the same name. I used this primarily to loop through controls, i.e.:
For i = 1 to 500
picSeat(i).Print "Hello"
Next i
Is there a way to do this in C#? I know there is a .IndexOf(), but would that really help for what I'm doing? I want to have multiple controls with the same name, just different index.
This is a Windows Form Application, and I'm using Visual Studio 2012. I am talking about controls, not arrays/lists; this was possible in VB and I was wondering if it was possible at all in C#. So I want to have, say, 30 seats in a theatre. I want to have each seat represented by a picturebox named "picSeat". VB would let me name several objects the exact same, and would assign a value to a control property "Index". That way, I could use the above loop to print "Hello" in every picture box with only 3 lines of code.
No, this feature does not exist in C#, and was never implemented in the transition from classic VB to VB.Net.
What I normally do instead is put each of the controls in question in a common parent container. The Form itself can work, but if you need to distinguish these from others of the same type a GroupBox or Panel control will work, too. Then, you access the controls like this:
foreach (var picBox in parentControl.Controls.OfType<PictureBox>())
{
// do something with each picturebox
}
If you want to use a specific control, just write by name:
pictureBox6.SomeProperty = someValue;
If you need to change a specific control determined at run-time, normally this is in response to a user event:
void PictureBox_Click(object sender, EventArgs e)
{
var picBox = sender As PictureBox;
if (picBox == null) return;
//picBox is now whichever box was clicked
// (assuming you set all your pictureboxes to use this handler)
}
If you really really want the Control Arrays feature, you can do it by adding code to create the array to your form's Load event:
PictureBox[] pictureBoxes = Me.Controls.OfType<PictureBox>().ToArray();
Are we talking WinForms here? I'm not sure, but I don't think you can have multiple controls in winforms with same name. But I vaguely recall doing something similar and the solution was to name them Button_1, Button_2 etc. Then you can iterate through all controls and get your own index.
Beware though that if you want to instanciate a separate control for each seat in a theatre, you might run into some serious performance issues :) I've done something similar to that as well and ended up drawing the whole thing on a canvas and using mouse coordinates to handle the events correctly.
You may want to check out the Uid property of controls.
(http://msdn.microsoft.com/en-us/library/system.windows.uielement.uid(v=vs.110).aspx)
You can access Control through Uid property with the following
private static UIElement FindUid(this DependencyObject parent, string uid)
{
var count = VisualTreeHelper.GetChildrenCount(parent);
if (count == 0) return null;
for (int i = 0; i < count; i++)
{
var el = VisualTreeHelper.GetChild(parent, i) as UIElement;
if (el == null) continue;
if (el.Uid == uid) return el;
el = el.FindUid(uid);
if (el != null) return el;
}
return null;
}
And simply use
var control = FindUid("someUid");
I copied code from this post
If you create an indexed dictionary of your user control, it will behave pretty much the same as in VB6, though you'll not see it on the VS C# GUI. You'll have to get around the placement issues manually. Still - and most importantly -, you'll be able to refer to any instance by the index.
The following example is for 3 pieces for clarity, but of course you could automate every step of the process with appropriate loops.
public partial class Form1 : Form
{
...
Dictionary<int, UserControl1> NameOfUserControlInstance = new Dictionary<int, UserControl1>()
{
{ 1, new UserControl1 {}},
{ 2, new UserControl1 {}},
{ 3, new UserControl1 {}}
};
private void Form1_Load(object sender, EventArgs e)
{
NameOfUserControlInstance[1].Location = new System.Drawing.Point(0, 0);
NameOfUserControlInstance[2].Location = new System.Drawing.Point(200, 0);
NameOfUserControlInstance[3].Location = new System.Drawing.Point(400, 0);
Controls.Add(NameOfUserControlInstance[1]);
Controls.Add(NameOfUserControlInstance[2]);
Controls.Add(NameOfUserControlInstance[3]);
}
...
}
I like using Tags to apply any type of meta data about the controls
for (int i = 0; i< 10; ++i)
{
Button button = new Button();
button.Tag = i;
}
This is an attempt to expand on this question. In my WPF program I've been cloning tabItems by using an XamlWriter in a function called TrycloneElement. I originally found this function here, but the function can also be viewed in the link to my previous question.
Now that I am beginning to worry about functionality inside my program, I found that the TrycloneElement function does not replicate any code-behind functionality assigned to the tabItem that it is cloning.
Because of High Core's link and comment on my earlier question I decided to start implementing functionality on my tabItems through Data Binding with my ViewModel.
Here is a sample of a command that I've implemented:
public viewModel()
{
allowReversing = new Command(allowReversing_Operations);
}
public Command AllowReversing
{
get { return allowReversing; }
}
private Command allowReversing;
private void allowReversing_Operations()
{
//Query for Window1
var mainWindow = Application.Current.Windows
.Cast<Window1>()
.FirstOrDefault(window => window is Window1) as Window1;
if (mainWindow.checkBox1.IsChecked == true) //Checked
{
mainWindow.checkBox9.IsEnabled = true;
mainWindow.groupBox7.IsEnabled = true;
}
else //UnChecked
{
mainWindow.checkBox9.IsEnabled = false;
mainWindow.checkBox9.IsChecked = false;
mainWindow.groupBox7.IsEnabled = false;
}
}
*NOTE: I know that I cheated and interacted directly with my View in the above code, but I wasn't sure how else to run those commands. If it is a problem, or there is another way, please show me how I can run those same commands without interacting with the View like I did.
Now to the question:
After changing my code and adding the commands to my ViewModel, the TrycloneElement function no longer works. At run time during the tab clone I receive an XamlParseException on line, object x = XamlReader.Load(xmlReader); that reads:
I'm fine with ditching the function if there is a better way and I don't need it anymore. But ultimately, how do I take a tabItem's design and functionality and clone it? (Please keep in mind that I really am trying to correct my structure)
Thank you for your help.
Revision of Leo's answer
This is the current version of Leo's answer that I have compiling. (There were some syntax errors)
public static IList<DependencyProperty> GetAllProperties(DependencyObject obj)
{
return (from PropertyDescriptor pd in TypeDescriptor.GetProperties(obj, new Attribute[] { new PropertyFilterAttribute(PropertyFilterOptions.SetValues) })
select DependencyPropertyDescriptor.FromProperty(pd)
into dpd
where dpd != null
select dpd.DependencyProperty).ToList();
}
public static void CopyPropertiesFrom(this FrameworkElement controlToSet,
FrameworkElement controlToCopy)
{
foreach (var dependencyValue in GetAllProperties(controlToCopy)
.Where((item) => !item.ReadOnly)
.ToDictionary(dependencyProperty => dependencyProperty, controlToCopy.GetValue))
{
controlToSet.SetValue(dependencyValue.Key, dependencyValue.Value);
}
}
Here is my example of a properly-implemented dynamic TabControl in WPF.
The main idea is that each Tab Item is a separate widget that contains its own logic and data, which is handled by the ViewModel, while the UI does what the UI must do: show data, not contain data.
The bottom line is that all data and functionality is managed at the ViewModel / Model levels, and since the TabControl is bound to an ObservableCollection, you simply add another element to that Collection whenever you need to add a new Tab.
This removes the need for "cloning" the UI or do any other weird manipulations with it.
1.) To fix that XamlParseException, make sure you have a public constructor like an empty one, you probably defined a constructor and when you tried to serialize that object and deserialize it can't. You have to explicitly add the default constructor.
2.) I don't like the word clone, but I'd say, when they want to copy. I'll manually create a new tab item control then do reflection on it.
I have this code that I made
public static IList<DependencyProperty> GetAllProperties(DependencyObject obj)
{
return (from PropertyDescriptor pd in TypeDescriptor.GetProperties(obj, new Attribute[] {new PropertyFilterAttribute(PropertyFilterOptions.SetValues)})
select DependencyPropertyDescriptor.FromProperty(pd)
into dpd where dpd != null select dpd.DependencyProperty).ToList();
}
public static void CopyPropertiesFrom(this FrameworkElement controlToSet,
FrameworkElement controlToCopy)
{
foreach (var dependencyValue in GetAllProperties(controlToCopy)
.Where((item) => !item.ReadOnly))
.ToDictionary(dependencyProperty => dependencyProperty, controlToCopy.GetValue))
{
controlToSet.SetValue(dependencyValue.Key, dependencyValue.Value);
}
}
So it would be like
var newTabItem = new TabItem();
newTabItem.CopyPropertiesFrom(masterTab);
How can you use a ListView to show the user a collection of objects, and to manage those objects?
For the purpose of argument, here's our design goal: We've got a "monster" object, and that "monster" will have several "powers." The user interacts with the powers via a ListView item.
First, we create a Power object. Give the object the following method:
public ListViewItem makeKey()
{
return new ListViewItem(name);
}
where name is the name of the power, and a string. This ListViewItem will serve as a key, allowing us to identify and retrieve this power later.
Next, we need to add somewhere in the Monster object to keep track of all these powers.
public Dictionary<ListViewItem,Power> powers;
So now we need a way to add powers to the monster.
public void addPower(Power newPower) {
ListViewItem key = newPower.makeKey();
monster.powers.add(key, newPower);
}
Ok, almost done! Now we've got a dictionary of ListViewItems which are tied to the monster's powers. Just grab the keys from that dictionary and stick them in a ListView:
foreach (ListViewItem key in powers.Keys)
powerList.Items.Add(key);
Where powerList is the ListView we're adding the ListViewItems to.
Alright, so we've got the ListViewItems in the ListView! Now, how do we interact with those? Make a button and then a function something like this:
private void powerRemoveButton_Click(object sender, EventArgs e)
{
if (powerList.SelectedIndices.Count > 0)
{
int n = powerList.SelectedIndices[0];
ListViewItem key = powerList.Items[n];
monster.powers.Remove(key);
powerList.Items.Remove(key);
}
else
{
MessageBox.Show("No power selected.");
}
}
And that's that. I hope you've found this helpful. I'm not sure if this was an intentional aspect of their design, but ListViews and Dictionaries blend together so amazingly well when you use a ListViewItem as a key that it's a joy!