I'd like to obtain a reference to underlying java components for the controls I have in my GUI so as to customize their appearance.
I know about findjobj from Yair Altman which works really well:
myLink = uicontrol('String', '<html><u>Button that looks like a link.</u></html>');
jObj = findjobj(myLink);
jObj.setContentAreaFilled(0);
Unfortunately this solution is quite slow when there are a "lot" of controls to customize (because it has to parse the full hierarchy of objects in the figure and this for each control to customize).
Moreover the figure must be visible (else controls are not instantiated and java references cannot be found). Plus it must be moved of screen to avoid users to touch it while findjobj is running (sometimes make things crash because findjobj somehow relies on position of controls to find them while internally calling also drawnow which updates positions) ...
On some machines, even with only a few controls to customize, it can be up to 10 seconds before to have the figure to appear (most of the time is spent in findjobj).
I also know about uicomponent again from Yair Altman to directly create controls and get the handle to the underlying java component in one shot:
[myLink, jObj] = uicomponent('Style', 'JButton', 'String', '<html><u>Button that looks like a link.</u></html>');
jObj.setContentAreaFilled(0);
Unfortunately here the parent property can only be a figure and of course my controls are placed in gui layout containers to handle resizing and many other things nicely (and gui layout containter are not valid hg-handles for uicomponent to work)...
So was wondering if there could be any other fast solution to get underlying java components for controls in my GUI ? ... NB: I mainly only need to have buttons that looks like hyperlinks or animated gif (i.e. borderless buttons with htlm text/img inside).
This isn't a direct answer to your question, but I've built several GUIs that are based around GUI Layout Toolbox and that contain Java swing components. I typically arrange things so that the GUI Layout container (HBox, VBox, Grid etc) has a uipanel as a child, and then the uipanel has the Java swing component as a child.
You can typically parent a Java component to the uipanel in exactly the same way as parenting it to a figure (unlike a GUI Layout container), and it's no problem to parent a uipanel to a GUI Layout container.
So, for example, to add a button with a dropdown menu (no menu items, so it won't do anything, but just to illustrate):
>> u = uipanel;
>> ddbuttonclass = 'com.mathworks.widgets.DropdownButton';
>> ddbutton = javaObjectEDT(ddbuttonclass);
>> [jddbutton, hjddbutton] = javacomponent(ddbutton, [30,30, 60, 30], u);
Now you can parent u to a GUI Layout container, and you get all the nice resizing.
I'm not that familiar with Yair's uicomponent, but if you can get the handle of the java component somehow, you should be able to use something like the above.
PS If you want his direct input, #Yair is sometimes active on SO - he may get notified if I mention his name. If you're doing a lot of Java/MATLAB GUI work, I'd also recommend buying his book.
UICOMPONENT was designed to be a direct replacement of both Matlab's built-in UICONTROL and JAVACOMPONENT functions. This means that you can directly place a UICOMPONENT within panels, even those created by the GUI Layout toolbox.
You might need to cast the layout panel's handle to double (double(hPanel)) on some Matlab releases but that's about it:
[myLink, jObj] = uicomponent('Parent',hPanel, ...);
[myLink, jObj] = uicomponent('Parent',double(hPanel), ...); % on some Matlab releases
You could also use JAVACOMPONENT directly, but it doesn't really give you any benefits over UICOMPONENT, since UICOMPONENT uses JAVACOMPONENT under the hood and also adds important functionality (such as ensuring the component is placed on the EDT, and merging important properties from the Matlab wrapper).
As for FINDJOBJ, you can speed it up a bit by specifying the target object class using the 'class' parameter. But if your figure contains hundreds of controls it might still be slow. To this day, close to 10 years after my first version of FINDJOBJ, I still do not know of a direct way to get the underlying Java object. I assume there is one that is used internally by MathWorks, but I do not know it.
As #SamRoberts mentioned, this is all discussed in my book...
Related
I'm trying to handle background color properly in a dynamically generated property sheet in dynamically generated property pages in win32 api using MFC (though I expect my question is general, and not restricted to MFC, but since my code and examples use it, it's germane to my question anyway).
So we have a:
CPropertySheet
containing multiple
CPropertyPage
I generate the contents of any given page dynamically - from file resources using a custom dialog definition language - all irrelevant other than to say - a list of controls and their coordinates is created within a given page, and the page is resized to accommodate them. This logic is working beautifully.
However, what doesn't work is that the controls and background of each page draws using the dialog default color/brush.
I've tried a number of ways to attempt to force it to draw using the white color/brush that a hard-coded property sheet / page would.
There are two important pieces to this:
Page Background
Control (on the page) background
For #1, I've tried:
acquire the background brush from parent window class (it's dialog bkgrd) (same is true if I do this and ask the tab control)
change the property page to use WS_EX_TRANSPARENT (PreCreateWindow is not called by the framework when generating a page viz PropertySheet::AddPage)
For #2, I've tried:
overriding OnWndMsg / WM_CTLCOLORSTATIC to forward that request to (A) the parent (sheet), and (B) to the tab control (which is what wants the white in the first place).
However, anytime I use any of the above "ask for the background / forward the request" up the chain to either the sheet or the tab control - I get the dialog background color, never the white I'd expect.
Using Spy64, I can see that for a fully hardcoded property sheet / page - that the only discernable differences I can see is that the dialog window created in AddPage (or its moral equivalent) has WS_CHILD instead of mine which has WS_POPUP (the rest of the styles appear to be the same, such as WS_VISIBLE|DS_3DLOOK|DS_FIXEDSYS|DS_SETFONT|DS_CONTROL and WS_EX_CONTROLPARENT.
So, other than the WS_CHILD, I see no significant differences from what I'm creating and from another property sheet that works properly from a standard resource (i.e. hard coded).
I'm also flummoxed as to how this works normally anyway - since forwarding things like the ctrlcolor message doesn't respond correctly - and asking for the windows background colors similar doesn't - then how is it in a standard case the background colors of controls and pages comes out as white, and not dialog background?
Any ideas or help would be appreciated - I'm kind of running out of ideas...
When Visual Styles were added in Windows XP they really wanted to show off this new feature so they made the tab background a gradient (really a stretched image) instead of a single color and this caused problems in old applications that did custom drawing with the dialog brush as the background.
Because of this, only applications with a comctl32 v6 manifest got the new look but there was a problem; old propertysheet shell extensions would load in new applications (including Explorer) and things would look wrong.
To work around this they also require you (or your UI framework) to call EnableThemeDialogTexture(.., ETDT_ENABLETAB) to get the correct tab page look.
As if things are not tricky enough, there is a undocumented requirement that you also need a button or a static control on the page!
If you have custom controls they have to call DrawThemeParentBackground when you draw if they are partially transparent.
Turns out my old code had defined an ON_WM_ERASEBKGND handler - and removing that (and all of my above attempts) makes it work.
So simply doing NOTHING is the correct answer. D'oh!!!
I'm leaving my shame here in case someone else trips on this! [Whoops!]
(Still interested if anyone has deeper insight into how this mechanism works under the hood)
New to GWT here...
I'm using the UIBinder approach to layout an app, somewhat in the style of the GWT Mail sample. The app starts with a DockLayoutPanel added to RootLayoutPanel within the onModuleLoad() method. The DockLayoutPanel has a static North and a static South, using a custom center widget defined like:
public class BigLayoutWidget extends ResizeComposite {
...
}
This custom widget is laid out using BigLayoutWidget.ui.xml, which in turn consists of a TabLayoutPanel (3 tabs), the first of which contains a SplitLayoutPanel divided into WEST (Shortcuts.ui.xml) and CENTER (Workpanel.ui.xml). Shortcuts, in turn, consists of a StackLayoutPanel with 3 stacks, each defined in its own ui.xml file.
I want click events within one of Shortcuts' individual stacks to change the contents of Workpanel, but so far I've only been able to manipulate widgets within the same class. Using the simplest case, I can't get a button click w/in Shortcuts to clear the contents of Workpanel or make WorkPanel non-visible.
A few questions...
Is ResizeComposite the right type of class to extend for this? I'm following the approach from the Mail example for TopPanel, MailList, etc, so maybe not?
How can I make these clicks manipulate the contents of panels in which they do NOT reside?
Are listeners no longer recommended for handling events? I thought I saw somewhere during compilation that ClickHandlers are used these days, and the click listener "subscription" approach is being deprecated (I'm mostly using #UiHandler annotations)
Is there an easy way to get a handle to specific elements in my app/page? (Applying the "ID" field in the UI.XML file generates a deprecation warning). I'm looking for something like a document.getElementById() that get me a handle to specific elements. If that exists, how do I set the handle/ID on the element, and how can I then call that element by name/id?
Note that I have the layout itself pretty well nailed; it's the interaction from one ui.xml modularized panel to the next that I can't quite get.
Thanks in advance.
If you don't have a use for resizing events than just use Composite
What you want is what the GWT devs called message bus (implemented as HandlerManager). You can get a nice explanation in the widely discussed (for example, on the GWT Google Group, just search for 'mvp') presentation by Ray Ryan from Google I/O 2009 which can be found here. Basically, you "broadcast" an event on that message bus and then a Widget listening for that event gets the message and does its stuff.
Yep, *Handlers are the current way of handling events - the usage is basically the same so migration shouldn't be a problem (docs). They changed it so that they could introduce custom fields in the future, without breaking existing code.
If you've set an id for any DOM element (for Widgets I use someWidget.getElement().setId(id), usually in combination with DOM.createUniqueId()) you can get it via GWT.get(String id). You'll get then a RootPanel which you'll have to cast to the right Widget class - as you can see it can get a little 'hackish' (what if you change the type of the Widget by that id? Exceptions, or worse), so I'd recommend sticking with MVP (see the first point) and communicating via the message bus. Remember however, that sometimes it's also good to aggregate - not everything has to be handled via the message bus :)
Bottom line is I'd recommend embracing MVP (and History) as soon as possible - it makes GWT development much easier and less messy :) (I know from experience, that with time the code starts to look like a nightmare, if you don't divide it into presentation, view, etc.)
In a tool such as Photoshop, there is a selection of tools you can click on (e.g. pen, brush etc). Once you click on a tool, you can use that tool to paint, erase etc depending on what tool is selected.
I'm wondering how that would be best implemented in an OO design. I could only think of having a GUIManager that always knows which tool is selected, then when the Canvas (drawing area) detects a mouse click or mouse drag it asks GUIManager which tool is selected and applies that tool's behavior.
Does anyone describe a possible solution in class level detail (or in any detail if you don't have time).
Take a look at the State Pattern which has exactly your example.
However, it's not actually a GUI question but more to an object-oriented approach to how to model this problem. The GUI doesn't really play into this.
I'm not sure OO principles really play into this except in the sense that all graphic elements are probably derived from common base classes in your GUI of choice.
The amount of complexity in an application that needs a hierarchy of screen menus à la photoshop would presumably dwarf the difference between composition vs inheritance vs functional-style vs whatever-you-want.
Although, should you be motivated to write the program twice using different styles, it might be interesting to see the results. The ranking of various programming styles is an open question without real answers at this point, although we think that OO-styles are important in a way we haven't yet completely quantified.
One idea for this would be to have a tool class. Just sketching this in C++-like pseudocode:
class Tool
{
public:
// Keep a pointer to the "document", i.e. some representation of the
// image you are editing
Tool(Document *pDoc);
// Process mouse events -- this need to be overridden to execute
// the appropriate behaviour depending on the concrete type of tool
virtual void OnMouseEvent(const MouseEvent &e) = 0;
// and so on
};
You then inherit from this abstract tool class to provide the concrete tools your application needs. When a certain tool is selected, you instantiate a corresponding tool object and remember it somewhere. The window forwards mouse events to the currently active tool object, which then does the appropriate thing for the tool that was selected.
This is an implementation of the State pattern that Johannes refers to.
Is there a way in Gtk+ to stack one widget on top of another -- not counting GtkFixed? GtkFixed doesn't work well for two reasons: 1) I need Z order, and 2) I need one widget to stretch and fill provided space.
I had this exact issue using a Gtk::Fixed (actually gtk.Fixed -- pygtk -- but I think it's all the same underneath) and I was able to handle it quite easily by manipulating each widget's window.
In my case, the widgets already are EventBox instances, and I just needed to make sure that the one I was dragging around was on top, because otherwise it slid underneath others, which looked quite wrong. The solution was as simple as calling "widget.window.raise_()" to raise the widget's underlying window when the widget was clicked to begin the drag.
So I'm basically just reaffirming that the previous answer works, but I wanted to point out that it's actually pretty easy. It sounds like you may need to create some EventBoxes to hold your widgets, but after that it should just work.
You can see the code I was working on at http://github.com/divegeek/BlockHead
I don't think there is a proper container in standard GTK. I would subclass Gtk::Fixed... it is still the closest one you can get, and if you use gtkmm then subclassing shouldn't be very difficult¹. Then you can control the dimensions of all widgets, stretching one selected child to fill space.
To control Z-axis you will probably need to manipulate widget's X windows--check GDK documentation on topic of GDK windows². I remember that in PyGTK each widget has gtk.Widget.window property, I guess that the same is for gtkmm. This assumes that all your child widgets have X windows, so f.e. you'll need to wrap Gtk::Label inside Gtk::EventBox.
¹ http://www.gtkmm.org/docs/gtkmm-2.4/docs/tutorial/html/chapter-customwidgets.html
² http://www.gtkmm.org/docs/gtkmm-2.4/docs/reference/html/classGdk_1_1Window.html#6eef65b862344ad01b01e527f2c39741
I was able to do exactly that -
display one widget filling the entire space, and then another on top at a fixed location, both visible at the same time
in gtk2 by using GtkFixed, working out a suitable insertion order (first inserted - bottom, last inserted - top), and - most importantly!! - forcing GtkFixed to have it's own window:
`f := gtk_fixed_new();
gtk_widget_set_has_window(f, 1);`
If you don't do set_has_window(f, 1), all children windows will be inserted into some parent widget/window (see gtk_fixed_realize() in gtkfixed.c), and that might create z-order mess.
I'm generating a MATLAB GUI using GUIDE, but I want to create fields when a user clicks on a button. Is there any way to dynamically add new GUI objects in the callbacks?
One way to accomplish this is to create the GUI objects at the start, but set their "Visibility" property to "off". Then, when the user clicks on a button, you set the "Visibility" property back to "on". This way, you won't be making new GUI objects while the GUI is running, you would simply be changing which parts of it are visible or not.
EDIT: If you don't know how many new GUI objects you need until run-time, this is how you would add the new GUI objects to the handles structure (where hFigure is a handle to the GUI figure):
p = uicontrol(hFigure,'Style','pushbutton','String','test',...
'Callback',#p_Callback); % Including callback, if needed
handles.test = p; % Add p to the "test" field of the handles structure
guidata(hFigure,handles); % Add the new handles structure to the figure
You would then of course have to write the callback function for the new GUI object (if it needs one), which might look something like this:
function p_Callback(hObject,eventdata)
handles = guidata(gcbf); % This gets the handles structure from the figure
...
(make whatever computations/changes to GUI are needed)
...
guidata(gcbf,handles); % This is needed if the handles structure is modified
Functions of interest that I used in the above code are: GUIDATA (for storing/retrieving data for a GUI) and GCBF (get handle of parent figure of the object whose callback is currently executing).
Using UICONTROL, you will be able to add 'fields' (called uicontrols or widgets).
You will want to specify the style to get edit boxes, buttons, etc...
You may actually want to have all the widgets already there in GUIDE and then just change the visibility or enabled property as needed.
You can find my video tutorials on GUI building in MATLAB here:
http://blogs.mathworks.com/videos/category/gui-or-guide/
This should cover this and many related topics in GUI building.