So i have a custom UISlider. It's vertical (i did it with the +270° technic). I have 3 images, respectively for the minimum value, maximum value and for the thumb. Everything seems good but i have problems with the extrema values, as you can observe on the screen capture (even though it's a little dark).
The slider on the left is perfect ! Both end of the sliders show the images perfectly and the cursor (thumb) is perfectly cutting the slider in 2.
The other two sliders on the right shows a similar issue. We can see that, when in extrema value, the cursor is not well located (there shouldn't be any part of the image below or above the middle of the cursor !) Oo
More to that, let's look at the right slider (with minimum value). We can see that image has been cut on the bottom ! Indeed it should be close. It's the same thing for the maximum value, the image looks like it's been cut.
I looked at the bounds of the slider view by touching it at both ends and looking at its coordinates. The slider was defined with a height of 300 but i can perform touches at coordinate 307, or -6 !!! I don't really understand why..
For more information, coordinates form 300 to 310 represents the maximum value i defined and negative coordinates (from 0 to -10) represents the minimum value.
-> So We can notice there's a difference of 10 at both ends.
Please help ! :s
Related
Context:
I'm working on a device which inserted between an electronic typewriter's controller and its keyboard turns it into a serial printer/terminal.
I want it to support some of the control sequences from ECMA-48 / ISO-6429 / ANSI X3.64. (also known as ANSI escape code)
I'm having some uncertainty if I'm understanding correctly the standard, so I would like to ask to know how it should be.
It's related to the commands SLH - SET LINE HOME and SLL - SET LINE LIMIT.
For example I could have the situation that I have 1/12 inch wide characters, I want a left margin of 1 inch, and 80 columns of text.
Then I would set page home to 13 and page limit to 92.
(since character positions are counted from 1, home is the first position, limit is the last)
So far ok.
But when I already have set the home, than how should the functions:
CHA - CURSOR CHARACTER ABSOLUTE
CUP - CURSOR POSITION
HPA - CHARACTER POSITION ABSOLUTE
CPR - ACTIVE POSITION REPORT
and others related to the cursor position work?
Should they use coordinates relative to to the actual edge, or to the home position.
So in my above example if I wanted to move to column 2 of the text print area (home being 13), I should use coordinate 2 or 14?
(similarly for vertical position and page home & limit)
My understanding is that these control sequences still use the absolute coordinates.
so in my example I would have to use coordinate 14.
Is this correct?
And if it is correct, this raises some additional problems:
I would have to know where the margins are to know which horizontal and vertical offset to use when moving the cursor to absolute positions.
If a program sets the margins first, then no problem, but I a program connects to the device and does not change the margins then it does not know the offset.
(There is a way, it could send a carriage return to move to the home position and then request the ACTIVE POSITION REPORT to discover the left margin position, but it does not look like a nice solution)
What should my device do if it is requested to move to a position outside the defined home and limit?
The standard says that beyond these limits no implicit movement should happen, but this is explicit movement.
If it receives a command to move to position 1 when the home is 13 what should it do? Move to 1? Move to 13? ignore?
When it is at position 15, home is at 13 and receives command to move cursor left by 4 positions should it move by 4 to 11? move by 2 to 13? ignore?
Another problem I see is that there is a command to set page home, and page limit, but not total page height.
It is only possible to select predefined formats by PFS - PAGE FORMAT SELECTION.
But I don't see a way to select any other height.
If I want to use continuous paper with 12 inch long pages (72 lines of text at 1/6 inch line height) connected together into a long tape then I see no way to define that height so that my device can correctly keep track of its positions on the following pages. Is there a way to do it?
Looks like I had to find the answers by myself.
question 0:
Yes, it appears, that the coordinates should still be absolute.
he standard says about character positions in a line and line positions in a page and these are specified in the beginning of the document and nowhere at all is said about it being relative. Looks like the only role of line home and limit is the place where CR (and some others) returns to, and limit of where implicit movement (like advancing forward after printing a character) can go, similar for page home and page limit.
question 1:
There is no easy way for a program to recognise where the home and limit positions are. As I mentioned, requesting ACTIVE POSITION REPORT can help if this is implemented. (my devece does not support it yet).
Anyway, many programs don't recognise the concept of line home, and assume that normal character positions start from 1.
My solution to this is that after power on, the line home IS exactly at position 1, and if you want something else, you have to specify it.
This way a program can safely make this assumption.
(However after the PFS - PAGE FORMAT SELECTION command I do set the line home to 1 inch as this is what the standard proposes)
question 2:
As above, the home and limit are only a margin for implicit movements. So the cursor movement commands will move outside these limits with no problem. Only the actual page size will limit them.
question 3:
(but I didn't give it a number when asked)
DTA - DIMENSION TEXT AREA is the command for this purpose. It specifies the size of the text area limited by the actual page size, not by the home and limit positions.
I have two axis in highcharts and I dont specify the range for either. Please see graph.
For some reason, series one from 201 to 206 is taking up the whole chart while series 2 which is only -2k to 2k is being squeezed to the bottom, thereby extending the range all the way to 30k which is totally unnecessary. I think highcharts by nature wants to not have any overlap but I want that. What I'd like is for the right series to be centered, in fact I want the right axis to be centered at 0 always and can grow unrestricted in either direction. I can't hardcode any of these since I have no idea what the values could be. So Series 1 on the left is ok, but I want the value 0 for series 2 to always start at the middle of the chart. Any way to achieve that?
Try to set alignTicks as false.
The problem is simple: I want to move (and later, be able to rotate) an image. For example, every time i press the right arrow on my keyboard, i want the image to move 0.12 pixels to the right, and every time i press the left arrow key, i want the image to move 0.12 pixels to the left.
Now, I have multiple solutions for this:
1) simply add the incremental value, i.e.:
image.x += 0.12;
this is of course assuming that we're going to the right.
2) i multiplicate the value of a single increment by the times i already went into this particular direction + 1, like this:
var result:Number = 0.12 * (numberOfTimesWentRight+1);
image.x = result;
Both of these approaches work but produce similiar, yet subtly different, results. If we add some kind of button component that simply resets the x and y coordinates of the image, you will see that with the first approach the numbers don't add up correctly.
it goes from .12, .24, .359999, .475 etc.
But with the second approach it works well. (It's pretty obvious as to why though, it seems like += operations with Numbers are not really precise).
Why not use the second approach then? Well, i want to rotate the image as well. This will work for the first attempt, but after that the image will jump around. Why? In the second approach we never took the original position of the image in account. So if the origin-point shifts a bit down or up because you rotated your image, and THEN you try to move the image again: it will move to the same position as if you hadn't rotated before.
Alright, to make this short:
How can i reliably move, scale and rotate images for 1/10 of a pixel?
Short answer: I don't know! You're fighting with floating point math!
Luckily, I have a workaround, if you don't mind.
You store the location (x and y) of the image in a separate variable... at a larger scale. Such as 100x. So 123.45 becomes 12345, and you then divide by 100 to set the attribute that flash uses to display.
Yes, there are limits to number sizes too, but if you're willing to accept some error rate, and the fact that you'll be limited to, I dunno, a million pixels in each direction, you can fit it in a regular int. The only rounding error you will encounter will be a single rounding error when you divide by 100 (or the factor you used). So instead of the compound rounding error which you described (0.12 * 4 = 0.475), you should see things like 0.47999999. Which doesn't matter because it's, well, so small.
To expand on #Pimgd answer a bit, you're probably hitting a floating point error (multiple +='s will exaggerate the error more than one *='s) - Numbers in Flash are 53-bit precision.
There's also another thing to keep in mind, which is probably playing a bigger role with such small movement values; Flash positions all objects using twips, which is roughly about 1/20th of a pixel, or 0.05, so all values are rounded to this. When you say image.x += 0.12, it's actually the equivalent of image.x += 0.10, hence which the different becomes apparent; you're losing 0.02 of a pixel with every move.
You should be able to get around it by moving to another scale, as #Pimgd says, or just storing your position separately - i.e. work from a property _x rather than image.x so you're not losing that precision everytime:
this._x += 0.12;
image.x = this._x;
I'm trying to customize a Coreplot graph in many ways I can and the next thing I would like to do is place the X Axis Labels (one that is custom as well) at the bottom of the graph, independent of the X axis' position (whether it's scrolled up or down).
To make it clear, it is similar to giving the labels an offset value of something like 50.0. But offset is not the property I'm looking for since it fixes the labels location relative to the X axis.
Any way this can be done? Or do I have to skip the axisLabels property and place and layer or something manually at the bottom of the graph?
EDIT: Alright, I managed to place an axis on the bottom with CPTConstraints. But it's not on the bottommost. If a plot point is on those levels, the plot line overlaps the labels. I tired padding of the graph but of course, it moves the whole graph, hence the issue persists.
Thanks in advance
Make a second x-axis. Have the first one draw the axis line, tick marks, etc., as normal but no labels. Label the second one and set all of the line style properties to nil so it doesn't draw any of the lines.
Turns out that aside from the graph, the plotAreaFrame property of the CPTGrpah also has paddings. If you give more paddings to plotAreaFrame than that of the graph, the plot will be drawn in a smaller frame and the rest of the graph area will be for you to add what you want (i.e., a second Axis).
Big thanks to #Eric, for trying to answer Every single CorePlot question as soon as possible.
CorePlot does have a lot of customisation than I thought.
I have a Delphi form with TImages on it. Actually, it's a "fake" desktop with "icons" (the TImages).
When the user resizes the form (scales it or maximizes it, for example) the icons on the form should align proportionally.
Right now, I'm doing something like this with the images:
ImageX.Left:=Round(ImageX.Left * (Width / OldWidth));
ImageX.Top:=Round(ImageX.Top * (Height / OldHeight));
Now this is OK, as long as I start to make the maximized form smaller.
In that case the rightmost images are cut in part by the form's border (they're off the form's client area).
If I reposition these images to fit the client area, then the position of the icons get distorted upon scaling back to maximum size.
Any ideas for a better algorithm/fix?
Thanks!
First of all, you can't have a correctly scaled desktop when you only move the images, and don't scale them as well. You can do slightly better by moving the midpoints of your images, not their top left corner. It still won't be perfect, but it will work better. Of course, now the images will be cropped on all four sides, not just bottom and right, but at least it will be symmetrical :-)
Second, you will get accumulative rounding errors since you constantly override the "original" values (ImageX's top and left coordinate). You'd be better off having the original values stored in some sort of collection or array, and setting the new position based on the original value, rather than the previous value.
Something like this:
ImageX.Left:=Round(ImageX_OriginalLeft * (Width / Original_Width));