Difference between revisions of "WxSmith tutorial: Building more complex window"

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(Let's check how does the window resize)
(Continue polishing the window)
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== Final words ==
Here we reach the end of this tutorial. Of course the window we've built is not in it's final shape and it could be adjusted - for example we could add some list remembering when and who borrowed the CD from us and who has it now, we could add some searching and so on. But to keep this tutorial quite short, I've decided to leave all those upgrades to you. I hope that you've learned something new and interesting here. Good bye and see you in next tutorial :)

Revision as of 23:59, 9 January 2008

Warning: unfinished

Building more complex window

Hi, in this tutorial I'll sow you some example of more complex window. Actually it would look complex when you start working with wxSmith. After writing few applications you will probably build few resources with this or even higher complexity so don't be scared. I'm working with wxSmith almost every day (it's really the best way to find bugs and discover nice improovements and that's what I should do as it's creator ;)) and athough edition may look comlex at the beginning, it's not hard to get used to it.

I also want you to know that as I'm writing the beginning of this tutorial, I'm also beginning of writing the application - I didn't prepared ready solution since I would like to show process of creating window in really natural way (maybe even with some mistakes), so while writing the tutorial I'll also create the application.

We will start with empty frame - if you've read previous tutorials you shouold create one without problems.

First task - some basic concept

My proposition for exmple application would be something to manage colleciton of CD-roms. So at the beginning we should realize what should be presented at the main window. Let's say that we would have most informations at the main window (although it may not be a very good assumption, it would help to show creation of more complex resources).

I would like to have some list of CD-roms on the left and some details of selected CD-rom on the right. So basically we have two regions in our window: one with the list and one with the details. I'd like also to use sizers because the application should be cross-platform and main window should be resizable.

Building skeleton

If want the application to look nice on both windows and linux, we should do some trick presented in the first tutorial - we had to add extra wxPanel into frame to make the background better. Let's to the same thing here:

  • First add wxBoxSizer directly into resource
  • Add wxPanel into that sizer
  • Set size of border to 0 to make the panel cover entine window

Now we should have some this result:

Wxs tut03 001.png

Now let's add wxBoxSizer into it - this sizer will manage out two main regions. After that the tree structure should look like this:

Wxs tut03 002.png

Now we can start filling those two regions - each one may have only one item (so the sizer we've just added will manage them). Usually in such sutiatuion I use wxStaticBoxSizer because we can mark regions and put some name for them. So let's add two wxStaticBoxSizer-s into the window. Be carefull while adding the second one because you may add it into the first region - always remember that parent for new items is always the item totally covered with blue:

Wxs tut03 003.png

To add second sizer properly you must click on the border surrounding the first one just like on the picture. Note that now the resource is small but it will change when we will add some items into regions.

Building the List of CDs region

Ok, now let's add some item which will show list of CDs. We can use wxListBox here:

Wxs tut03 004.png

The list is rather small so let's resize it using drag-boxes to something bigger and higher:

Wxs tut03 005.png

Ok, but the second sizer did not resize. That's right since we didn't turn on it's Expand' flag. To do this let's click on the second sizer and check it's Expand property:

Wxs tut03 006.png

Now we can change labels of regions since they are fully visible now. To do this click on each region's sizer and change the Label property:

Wxs tut03 007.png

Ok but we would like to have ability to add and delete selected cd - we will insert two buttons for this purpose in the first region. To add the button choose it from palette and add into the sizer. Note that we can now point wxListBox item - it can not have children so wxSmith will try to add new item before or after it. After adding button we would have such result:

Wxs tut03 008.png

Hmm, the button should be under the list, not next to it. wxStaticBoxSizer did align items as it should - by default it aligns them in horizontal line. To change the direction to vertical, you can change the Orientation property of wxStaticBoxSizer. But before we change it let's predict one more thing. I would like to have two buttons instead of only one and I'd like them to be aligned horizontally. Since wxStaticBox will be changed to vertical mode, we will have to use another sizer used only for buttons. So let's add wxBoxSizer right after the list and before button:

Wxs tut03 009.png

Now let's change Orientation of the wxStaticBoxSizer to vertical. After changing we have following result:

Wxs tut03 010.png

We can see that something's wrong here. The wxBoxSizer is abnormally stretched and if we scroll the editor we can see that the same goes to button. We said in previous tutorial that wxBoxSizer an wxStaticBoxSizer are trying to keep same size of items in one direction - that's what happened here. wxStaticBoxSizer used the highest item (list of CDs) and applied this height into all managed items. How to disable it? By setting Proportion property of both wxBoxSizer and wxButton to 0. This will notify that those items shouldn't be used in height calculations:

Wxs tut03 011.png

Now let's move the button into the wxBoxSizer - you can very easily do it by clickong on the button and dragging it into the sizer. After that we can add second button next to the first one:

Wxs tut03 012.png

Nowe we can see that the list don't have Expand property set (otherwise it would be almost as wide as the region.

Now I'd like to see how current work does look in the application. We could simply run it (F9) or by pressing the preview button on the right part of wxSmith editor:

Wxs tut03 013.png

(If you run application you will see that there's menu and statusbar, on the preview it won't show, wxSmith still misses few features ;) )

Our window looks good, not perfect but let's leave some polishing for later and fill the CD details region.

Building CD details region

Inside CD details I'd like to have description of CD:

  • Type (Music/Program/Backup/Other)
  • Title
  • Artist/Author
  • Date of release
  • Description

For such list we would need some grid sizer. Ok, but the region has wxStaticBoxSizer which align items only in one line. To overcome this limitation we can just add another sizer into wxStaticBoxSizer and use new one as the grid. From two available sizers I suggest wxFlexGridSizer (wxGridSizer would force all cells to have same size which wouldn't look good because row with description may need some more space than others). So let's add new sizer:

  • Add wxFlexGridSizer into wxStaticBoxSizer
  • Check Expand property of new item
  • Set Border Size to 0 to avoid some unwanted border.

Adding items

Data presented here should be shown in two columns - first for the label and second for value so let's change the Cols property to 2. And now it's time to add the content. For labels we will use wxStaticText and for the value we will use different items:

  • wxChoice for Type
  • wxTextCtrl for Title, Artist/Author and Description
  • wxDatePickerCtrl for Date of release

After adding items we should have following view:

Wxs tut03 014.png

Hmm, as I've said at the beginning - I didn't prepared anything before writing this tutorial. And guess what. It looks like wxDatePickerCtrl is broken on linux and sometimes crashes C::B (I didn't check on windows), don't know yet whether it's in wxWidgets or wxSmith - I'll have to investigate it. So we will have to change wxDatePickerCtrl to something else or remove it.

There's alternative for wxDatePickerCtrl - wxCallendarCtrl so first let's try to replace wxDatePickerCtrl. First we will have to remove wrong item (by using 'delete' key or by pressing 'X' button on the right side of the editor). After the change we can see that generated callendar is quite but according to other items in this region. We can shrink it a little bit by checking wxCAL_SEQUENTIAL_MONTH_SELECTION inside the Style property but it will make the item harder to navigate. We can additionally set wxSUNKEN_BORDER style to add some nice border around the callendar. Ok, not perfect but acceptable ;)

Now we have this screen:

Wxs tut03 015.png

Customizing and adjusting items

Ok, it looks like we have few things to do now:

  • First is to check Expand property for the first region since (it didn't expand when the second region increased height)
  • Second is to set proper labels for values in CD details region
  • Third is to check Expand property for all items with values in same region
  • Fourth thing is to adjust items used to edit values in CD details region

First three tasks are quite easy and I'll leave them to you :)

Fourth task will require few new things so I'll describe it better:

First let's remove text from text boxes - it's set by default but it would be better to have empty text by default. Text can be changed by modifying Text property so you should do this very quickly.

Now we have to set some values which could be choosen from Type value. It's done by editing Choices property of wxChoice. This is more advanced value consisting of few strings to entering it inside one line of text could be hard. Because of that, instead of text, there's a button on the right side. When you click it, new window will pop-up where you can enter choices:


Let's check how does the window resize

We have the first version of our window. But it's not the end of work. If we want it to be user-friendly, it should give ability to resize. We can check it by either showing preview or building and running application. The latter is preffered since it may produce better results. If the window will show, we should experiment by resizing it:

Wxs tut03 016.png

We can see two wrong things in this window:

  • Regions did not expand vertically and stay centered
  • Content of second region did not react for the resize

The first problem should be cuased by some missing Expand property so let's find it.

First we should check if regions have Expand property set: yes they have so this is not the problem. Generally in such situations we should continue checking in parent item - this is wxBoxSizer which always expand. Next there's wxPanel we used to make nice background and voila: this one does miss the Expand property. So let's check it and test the result again and it works fine.

Now the second issue. Content inside CD details pane was based on wxFlexGridSizer. If you look into previous tutorial you may find out that this sizer has special property called Growable cols. Using this property we can set columns which should resize. I'd like the column with values to grow (we don't need more space for labels, dont we? ;) ) so let's set the Growable cols to "1" (idexes are 0-based). Note that you may quickly find the wxFlexGridSizer by ooking into resource tree - we have only one such sizer in our project.

Now we have some more correct results:

Wxs tut03 017.png

Continue polishing the window

As I look into our window I see that I left few things on the first region. Buttons don't have new labels and there's to much space between them and the list so we can update those things right now.

As usual I'll leave changing the Labels to you - those buttons should be called Add and Delete. And now let's remove the wasted space.

The space is added because each item inside sizers may have extra border. By default it's set to 5 pixels so if we remove the border around buttons we would have more free space. But than the buttons won't have any space between them.

To overcome this problem we could use another property related to border also called Border (jay, I have to fix the naming before someone notice it) which expands to few check-boxes. By checking or unchecking them we can enable or disable border at some item's edge. So if we remove top/bottom/left edge borders of the first button and top/bottom/right edge borders of the second button we would remove extra space but buttons will still have some gap between them. Here's how the property should look like for the first button:

Wxs tut03 018.png

Final words

Here we reach the end of this tutorial. Of course the window we've built is not in it's final shape and it could be adjusted - for example we could add some list remembering when and who borrowed the CD from us and who has it now, we could add some searching and so on. But to keep this tutorial quite short, I've decided to leave all those upgrades to you. I hope that you've learned something new and interesting here. Good bye and see you in next tutorial :)