i have a listfield where i am adding the contents in a horizontal field manager first and then adding the manager to a vertical manager. Visually:
----Image ---Text ----Image
---Text ----Image
---Image
How can i achieve this using a horizontal field manager
You might want to clear up the question a bit, but I'll try to answer what I think you're asking. ListFields don't support (natively) drawing a Manager as its row -- or a Field for that matter. What you'll need to do is in your ListFieldCallback's drawListRow() method, emulate this by doing the painting the way you want it to look. It would end up being measurements with bitmap.getWidth() and font.getAdvance(text) to figure out where to draw the images and text, but it should be a simple enough process.
Related
I would like to add an icon to the header of my data grid as it is done in Thunderbird.
There is an icon that is above the vertical scrollbar, no matter the position of the horizontal scrollbar. This icon allows the setup of the columns.
In Delphi there a lot of different grid components, that allow customizations and adding icons to there cells / header cells. But I could not find any component that has an area above the vertical scrollbar that is fixed, which when clicked allows some action. I could even use the VirtualTreeView component to emulate the grid, if it turns out to be easier to customize that component.
I am looking for some guidance on what need to be done to get that functionality.
Thanks,
Thomas
VirtualTreeView in Listbox mode would be nice, because of it's speed, great documentation and ease use in MVC-like patterns. Delphi tempts to store data in the visual components themselves, which letter causes troubles. While VTW allwos the same, it also allows to acutally separate data from GUI, and i like it.
But i am surprised by your claim "which when clicked allows some action.".
Even most basic components allow it:
http://docwiki.embarcadero.com/Libraries/XE2/en/Vcl.Grids.TCustomGrid.OnFixedCellClick
So could you make more detaiils, why you cannot use standard components ? with screenshot and editors, how u want it rendered, where you want to click and what kind of action should happen ?
My requirement is to create a customlistfieldmanager by extending verticalfeildmanager, I am not able to figureout how to do this?
I am not able to understand why my manager has asked me to use this method.
any sort of help is welcomed!
It's possible that he's asked you to do this because of the most limiting factor of a normal ListField: you're stuck with uniform heights.
What you'll need to do is have a parent container that is a scrolling VerticalFieldManager. Inside of that will be custom Managers that can handle the same functionality as the row would in a ListField. It needs to accept focus and fire off an event when it's clicked. You'll also need to keep track of what item number it is, so that when it's clicked it knows how to notify any listeners about which one was selected. Also, the parent VFM will need to be able to keep track of which "row" is currently selected -- in this case which one has focus.
Edit for comment
If you add a NullField into each of them it can accept focus but won't actually show up as anything. To determine if a "row" (the Manager) has focus, you can use getFieldWithFocus() on that Manager and the one that doesn't return null is the row that is selected. You will probably also have to do some custom painting to draw the selection highlight
You will have to dynamically add and remove custom elements from your CustomListFieldManager as you add and remove elements from a VerticalFieldManager.
Your manager asked that because he want you to learn how to handle custom object to understand how to use managers.
Hello I am new to Blackberry , Can any one tell me that how to add Vertical Field Manager in to Tree View?
TreeField is not designed for this. It is not a Manager, so you can't add any child fields to it. Similar to ListField the TreeField is a way to represent on UI a potentially large data structure without eating too much RAM (since in this case there is the only UI object - the TreeField).
I'm looking for a way to insert emoticons/smileys/any bitmap in a text field (LabelField, EditField, whatever). From what I've researched so far, there is no direct way to do this, so I'm stuck with trying to simulate this behavior.
I was thinking of using a normal text field and instead of smileys to insert blank spaces and then place some BitmapFields over the text field where the smileys should be. The problem is that I have no reliable/quick way of finding a character's position on screen (x,y).
Can you give me some ideas?
Can you think of other approaches to this problem?
I'm sure a lot of people encountered this kind of problem at one time or another. I hope there is someone who managed to find a solution. I'm desperate enough to accept any solution, no matter how crazy/complex/difficult.
Also, I would like to use this in SDK 5.0 and up, but I will settle for only 6.0.
What you might be able to do is create a custom Manager that is a container for EditFields and BitmapFields. When the user clicks in the initial EditField that is inside of your Manager and begins typing, you let them type until they want an emoticon. When they select it you create a BitmapField right after the EditField and then place a new EditField to the right of the BitmapField. You'll have to keep track of things like when the user hits backspace and empties an EditField, it should be removed, and then they are selecting the BitmapField, and a subsequent backspace would delete the BitmapField and put focus on the previous EditField.
You will have to also create your own EditField that you can control the size of, and BitmapField that allows for backspace to delete it.
As far as I can think ahead, you shouldn't have any problem using this for 5.0
Edit for comments:
You'll have to be implementing your own sublayout() of your Manager in any approach you take, so you know positions because you're the one who put them there. If you want to want to do multi-line (my approach was for single-line), you can do one of three things:
1.) Just have new EditFields for each line and do the linking the same way I talked about where backspace drops you to the previous Field, in this case the last line. You have to keep measurements of how big the field is based off of the text, and see if that will move it to the next line. If it does just adjust where the EditFields are positioned.
2.) You can do your image placement in the multi-line field by implementing your own EditField that expands height, in which case you'll know where the text is and what lines you are on. Drawing the Bitmap would be a matter of calculating (what line number you are) * (font height) and getAdvance(text_up_to_bitmap).
3.) Implement your own EditField where you have a focusable Manager that you manually do all of the drawing. You can parse a String that you save from capturing key strokes and maybe have a flag where an emoticon should be. Draw the text before it, draw the emoticon, then continue drawing the text. The difficulty with this is you will have to do things like determining where the cursor should be, bringing up the virtual keyboard, and handling some of the other tasks that the EditField does for you.
Is it possible to add gui components to blackberry screen beginning from the bottom instead of the top ?
Thanks
A quick response would be no but let me explain why and suggest afew work arounds;
Screens don't actually handle the laying out of fields onto themselves, to do this they delcare a delegate manager which can be any type of manager, vertical, horizontal etc. The problem is all managers begin painting themselves from the top left. For a manager to paint fields starting from the bottom it would have to know exaclty where the bottom is located and add components up rather than down which goes against all the low level code inside the manager class. You can read more on managers in the BlackBerry API documentation.
You could still achieve an effect similar to this though by tweaking how you add fields and playing with field styles. For example consider this code:
add(new LabelField("field 1"));
add(new LabelField("field 2"));
This would give us the results;
field 1
field 2
because field 1 is drawn then field 2 below it. However if we were always to insert fields at the begining of our manager e.g. position 0 like so:
insert(new LabelField("field 1", FIELD_BOTTOM), 0);
insert(new LabelField("field 2", FIELD_BOTTOM), 0);
We would get the results;
field 2
field 1
Which is the results you'd expect from a screen described in your question.
I'm not really sure how you'd get the fields to paint to the bottom of a screen though, you could try researching the "position relative bottom" styles but I'm honestly unsure.
You are probably using a VerticalFieldManager, and the documentation on that says:
A vertical field manager lays out
fields top to bottom in a single
column.
So if you
manager.add(field1);
manager.add(field2);
manager.add(field3);
The order of the fields on the screen will be just that.
But you could do something like this:
Vector v = new Vector();
v.add(field1);
v.add(field2);
v.add(field3);
for(int i=v.size()-1;i>=0;i--) {
manager.add((Field)v.elementAt(i));
}
Sort of. You can use the Manager#insert(Field, int) method and always insert at the zero index. If you do this with a VerticalFieldManager, it would simulate a bottom-up adding of Fields to the Manager.
Some of the answers so far are to use Manager.insert(Field, int), and keep inserting at position 0. This will work, but the running time of the insert is linear in the number of elements already added to the manager. Meaning this solution will have an overall quadratic running time. Not a big deal if you're adding under 10 fields, but if you're planning on adding more than that, the insert overhead will be substantial.
If you can do the inserts top to bottom, by reordering the fields as Muger's solution suggests, the running time will be much improved.
Finally, you can write your own BottomUpVerticalFieldManager that does the layout the way you want. When you write your own manager, you can layout the fields in whatever way pleases you. In this case, it would be bottom to top. Writing your own manager may seem daunting, but it will give you considerable freedom in the future when trying to solve layout issues.