I have an Android project that uses several containers inside a Grid Layout.
The containers' height and width are different and I am looking for a way to make them square.
I have tried it the following way:
int w = container.getWidth();
container.setHeight (w);
This does not not work, because:
a) container.setHeight(i) does not change the height of the container, and
b) container.getWidth() returns 0.
What would be the best approach to obtain square containers?
EDIT
Here is a updated screenshot: left is before, right is after using the code sample.
Size is set by the layout manager. The layout manager effectively invokes setWidth/Height/X/Y to determine the bounds of the components. So any change you make to any one of those methods will be overridden by the layout manager.
To explicitly define the size override calcPreferredSize() and return a uniform size ideally one that is calculated and not hardcoded e.g.:
Container myContainer = new Container(new GridLayout(1, 1)) {
#Override
protected Dimension calcPreferredSize() {
Dimension d = super.calcPreferredSize();
int size = Math.max(d.getWidth(), d.getHeight());
d.setWidth(size);
d.setHeight(size);
return d;
}
};
Related
I created an app to calculate the sizes of a multi-image, in order to use them in the Codename One designer.
As you can see in the screenshot below, my app has a slider and I get the width (in millimeters) of it. The problem is that the value of the selected width is incorrect. I tested the app on two Android devices and the measured lengths are different from the ones reported by the app.
You can see the full source code, however the relevant code is the following:
Label value = new Label("Move the cursor on the slider...");
Style thumbStyle = new Style();
thumbStyle.setFont(Font.createSystemFont(Font.FACE_MONOSPACE, Font.STYLE_BOLD, Font.SIZE_LARGE), true);
Slider slider = new Slider();
slider.setMaxValue(1000);
slider.setMinValue(0);
slider.setProgress(20); // Set the starting value
slider.setThumbImage(FontImage.create("|", thumbStyle));
slider.setEditable(true); // to it works as a slider instead of a progress bar
slider.addActionListener(e -> {
Integer valueSelected = slider.getProgress();
Integer sliderWidth = slider.getWidth();
Double inch = sliderWidth.doubleValue() / (slider.getMaxValue() - slider.getMinValue()) * valueSelected / 100.0;
Integer millimeters = Double.valueOf(inch * 25.4).intValue();
value.setText("Value selected: " + millimeters.toString() + " mm");
});
Thank you very much for any help
Millimeter measures aren't accurate. A device can return different values or ratios for the convert method than the value it returns for the density flag.
Unfortunately, Googles test suite to certify a device as "good" doesn't actually cover these things. There isn't much we can do about that.
At this moment I'm only testing my app in the simulator (as I'm having issues with "Send iOS Build" mentioned in another thread [Errors with Codename One "Send iOS Build" and "Send Android Build")
I'm experiencing some layout issues where it is not making use of the width and height correctly. The elements are left-aligned and there is unused space on the right side. And I need to scroll up and down instead of having everything fit within the visual area. Please see images.
The code are:
private final void show() {
loginSignupForm = new Form("Company", new BoxLayout(0));
Tabs loginSignupTabs = new Tabs();
Style loginSignupStyle = UIManager.getInstance().getComponentStyle("Tab");
prepareAndAddSignupTab(loginSignupTabs, loginSignupStyle);
prepareAndAddLoginTab(loginSignupTabs, loginSignupStyle);
loginSignupForm.add(loginSignupTabs);
loginSignupForm.show();
}
private void prepareAndAddLoginTab(Tabs loginSignupTabs, Style loginSignupStyle) {
loginID = new TextField();
loginPassword = new TextField();
Button loginButton = getLoginButton();
Component[] loginComponents = {
new Label("Email Address"),
loginID,
new Label("Password"),
loginPassword,
loginButton,
};
Container loginContainer = BoxLayout.encloseY(loginComponents);
FontImage loginIcon = FontImage.createMaterial(FontImage.MATERIAL_QUESTION_ANSWER, loginSignupStyle);
loginSignupTabs.addTab("Login", loginIcon, loginContainer);
}
What do I need to changenter code heree to get the elements to:
1. expand to the maximum width (no free space on the right)
2. fit within the visual area (for top-to-bottom)
Please note that I'm coding the elements because I find the (new) GUI Builder quite a challenge to use.
Firstly, don't pass a constant value as an argument to Layouts, coz the values might change in future Codename One updates and this will be difficult for you to debug. new BoxLayout(0) should be new BoxLayout(BoxLayout.Y_AXIS) or simply BoxLayout.y().
The above is where the problem arose but not the only problem because BoxLayout doesn't recognize 0 as a valid argument as it has only 3 which are X_AXIS = 1, Y_AXIS = 2, and X_AXIS_NO_GROW = 3.
If you change the above to use BoxLayout.Y_AXIS, it will work, but from the screenshot above, that's not the best solution.
In conclusion, change your code to below:
private final void show() {
loginSignupForm = new Form("Company", new BorderLayout());
Tabs loginSignupTabs = new Tabs();
Style loginSignupStyle = UIManager.getInstance().getComponentStyle("Tab");
prepareAndAddSignupTab(loginSignupTabs, loginSignupStyle);
prepareAndAddLoginTab(loginSignupTabs, loginSignupStyle);
loginSignupForm.add(BorderLayout.CENTER, loginSignupTabs);
loginSignupForm.show();
}
I used the (new) GUI Builder and inserted an image (by way of adding a Label). However, it appears too big. Is there anyway I can scale and control the size? (I saw something which points to cloudinary but that seems too complicated. I just want to simply scale down the image.)
There are several ways to resize images in Codename One and I will mention few below:
1.
Use MultiImages in the GUI Builder. With this multiple sizes of images are generated from one image based on the sizes you specified. In your GUI Builder, Click Images -> Add Multi Images -> Select your image -> Check Preserve Aspect Ratio -> Increase the % that represents the percentage of the screen width you want the image to occupy. Set any DPI you don't require to 0.
2.
Use ScaledImageLabel or ScaledImageButton, it will resize the image the fill available space the component is occupying.
3.
Scale the image itself in code (This is not efficient, though):
public static Image getImageFromTheme(String name) {
try {
Resources resFile = Resources.openLayered("/theme");
Image image = resFile.getImage(name);
return image;
} catch (IOException ioe) {
//Log.p("Image " + name + " not found: " + ioe);
}
return null;
}
Image resizedImage = getImageFromTheme("myImage").scaledWidth(Math.round(Display.getInstance().getDisplayWidth() / 10)); //change value as necessary
4.
Mutate the image (Create an image from another image).
So, I have a LoaderMax instance loading images from various URLs. I want to add all loaded images to an array.
Here's my code:
var photosArray:Array = new Array(5);
var imageLoadingQueue:LoaderMax = new LoaderMax({name:"mainQueue", onComplete:completeHandler});
for (var g:uint=0; g<5; g++)
{
imageLoadingQueue.append(new ImageLoader("/img" + g + ".jpg", {name:"photo", container:photosArray[g], noCache:false, smoothing:true, width:126, height:126, scaleMode:"proportionalOutside"}));
}
imageLoadingQueue.load();
private function completeHandler(e:LoaderEvent):void
{
trace("finished loading pictures!");
//the next two lines will return an error (saying that photosArray[1] is null)
stage.addChild(photosArray[1]);
photosArray[1].x = 250;
}
A few problems:
If I set the container of the image being loaded to the Array, it won't work. I'm not being able to access the image inside the array because it says it's null.
If I set the container of the image being loaded to "this" (using the container property when appending a new ImageLoader) and, on the completeHandler, set my array equal to event.target.content, it kinda works (but it's not the ideal). The problem is that, by doing so, the images are appearing on the stage as they are loaded, and I do no want them to do so.
Any help would be heavily appreciated.
Thanks!!
David is correct, but I also wanted to mention that the LoaderMax's "content" is actually an array of all of its children's content, so you could just use that for simplicity. Keep in mind that ImageLoaders automatically create a Sprite (technically called a "ContentDisplay") to drop the image into so you probably don't need to create ANOTHER Sprite (a container for the container).
var photos:Array = imageLoadingQueue.content;
stage.addChild(photos[1]);
The other nice thing is that it creates the ContentDisplay Sprites immediately, even before any content is loaded into them, so you can place them and size them however you want while (or before or after) loading occurs.
The container needs to be a DisplayObjectContainer. ImageLoader will try to add the image to the container using addChild(), so obviously this won't work with an empty array. Create a new Sprite for each image and add it into the array first:
for (var g:uint=0; g<5; g++)
{
photosArray[g] = new Sprite();
imageLoadingQueue.append(new ImageLoader("/img" + g + ".jpg", {name:"photo", container:photosArray[g], noCache:false, smoothing:true, width:126, height:126, scaleMode:"proportionalOutside"}));
}
What's the best way to convert a WPF (resolution-independent) width and height to physical screen pixels?
I'm showing WPF content in a WinForms Form (via ElementHost) and trying to work out some sizing logic. I've got it working fine when the OS is running at the default 96 dpi. But it won't work when the OS is set to 120 dpi or some other resolution, because then a WPF element that reports its Width as 96 will actually be 120 pixels wide as far as WinForms is concerned.
I couldn't find any "pixels per inch" settings on System.Windows.SystemParameters. I'm sure I could use the WinForms equivalent (System.Windows.Forms.SystemInformation), but is there a better way to do this (read: a way using WPF APIs, rather than using WinForms APIs and manually doing the math)? What's the "best way" to convert WPF "pixels" to real screen pixels?
EDIT: I'm also looking to do this before the WPF control is shown on the screen. It looks like Visual.PointToScreen could be made to give me the right answer, but I can't use it, because the control isn't parented yet and I get InvalidOperationException "This Visual is not connected to a PresentationSource".
Transforming a known size to device pixels
If your visual element is already attached to a PresentationSource (for example, it is part of a window that is visible on screen), the transform is found this way:
var source = PresentationSource.FromVisual(element);
Matrix transformToDevice = source.CompositionTarget.TransformToDevice;
If not, use HwndSource to create a temporary hWnd:
Matrix transformToDevice;
using(var source = new HwndSource(new HwndSourceParameters()))
transformToDevice = source.CompositionTarget.TransformToDevice;
Note that this is less efficient than constructing using a hWnd of IntPtr.Zero but I consider it more reliable because the hWnd created by HwndSource will be attached to the same display device as an actual newly-created Window would. That way, if different display devices have different DPIs you are sure to get the right DPI value.
Once you have the transform, you can convert any size from a WPF size to a pixel size:
var pixelSize = (Size)transformToDevice.Transform((Vector)wpfSize);
Converting the pixel size to integers
If you want to convert the pixel size to integers, you can simply do:
int pixelWidth = (int)pixelSize.Width;
int pixelHeight = (int)pixelSize.Height;
but a more robust solution would be the one used by ElementHost:
int pixelWidth = (int)Math.Max(int.MinValue, Math.Min(int.MaxValue, pixelSize.Width));
int pixelHeight = (int)Math.Max(int.MinValue, Math.Min(int.MaxValue, pixelSize.Height));
Getting the desired size of a UIElement
To get the desired size of a UIElement you need to make sure it is measured. In some circumstances it will already be measured, either because:
You measured it already
You measured one of its ancestors, or
It is part of a PresentationSource (eg it is in a visible Window) and you are executing below DispatcherPriority.Render so you know measurement has already happened automatically.
If your visual element has not been measured yet, you should call Measure on the control or one of its ancestors as appropriate, passing in the available size (or new Size(double.PositivieInfinity, double.PositiveInfinity) if you want to size to content:
element.Measure(availableSize);
Once the measuring is done, all that is necessary is to use the matrix to transform the DesiredSize:
var pixelSize = (Size)transformToDevice.Transform((Vector)element.DesiredSize);
Putting it all together
Here is a simple method that shows how to get the pixel size of an element:
public Size GetElementPixelSize(UIElement element)
{
Matrix transformToDevice;
var source = PresentationSource.FromVisual(element);
if(source!=null)
transformToDevice = source.CompositionTarget.TransformToDevice;
else
using(var source = new HwndSource(new HwndSourceParameters()))
transformToDevice = source.CompositionTarget.TransformToDevice;
if(element.DesiredSize == new Size())
element.Measure(new Size(double.PositiveInfinity, double.PositiveInfinity));
return (Size)transformToDevice.Transform((Vector)element.DesiredSize);
}
Note that in this code I call Measure only if no DesiredSize is present. This provides a convenient method to do everything but has several deficiencies:
It may be that the element's parent would have passed in a smaller availableSize
It is inefficient if the actual DesiredSize is zero (it is remeasured repeatedly)
It may mask bugs in a way that causes the application to fail due to unexpected timing (eg. the code being called at or above DispatchPriority.Render)
Because of these reasons, I would be inclined to omit the Measure call in GetElementPixelSize and just let the client do it.
Simple proportion between Screen.WorkingArea and SystemParameters.WorkArea:
private double PointsToPixels (double wpfPoints, LengthDirection direction)
{
if (direction == LengthDirection.Horizontal)
{
return wpfPoints * Screen.PrimaryScreen.WorkingArea.Width / SystemParameters.WorkArea.Width;
}
else
{
return wpfPoints * Screen.PrimaryScreen.WorkingArea.Height / SystemParameters.WorkArea.Height;
}
}
private double PixelsToPoints(int pixels, LengthDirection direction)
{
if (direction == LengthDirection.Horizontal)
{
return pixels * SystemParameters.WorkArea.Width / Screen.PrimaryScreen.WorkingArea.Width;
}
else
{
return pixels * SystemParameters.WorkArea.Height / Screen.PrimaryScreen.WorkingArea.Height;
}
}
public enum LengthDirection
{
Vertical, // |
Horizontal // ——
}
This works fine with multiple monitors as well.
I found a way to do it, but I don't like it much:
using (var graphics = Graphics.FromHwnd(IntPtr.Zero))
{
var pixelWidth = (int) (element.DesiredSize.Width * graphics.DpiX / 96.0);
var pixelHeight = (int) (element.DesiredSize.Height * graphics.DpiY / 96.0);
// ...
}
I don't like it because (a) it requires a reference to System.Drawing, rather than using WPF APIs; and (b) I have to do the math myself, which means I'm duplicating WPF's implementation details. In .NET 3.5, I have to truncate the result of the calculation to match what ElementHost does with AutoSize=true, but I don't know whether this will still be accurate in future versions of .NET.
This does seem to work, so I'm posting it in case it helps others. But if anyone has a better answer, please, post away.
Just did a quick lookup in the ObjectBrowser and found something quite interesting, you might want to check it out.
System.Windows.Form.AutoScaleMode, it has a property called DPI. Here's the docs, it might be what you are looking for :
public const
System.Windows.Forms.AutoScaleMode Dpi
= 2
Member of System.Windows.Forms.AutoScaleMode
Summary: Controls scale relative to
the display resolution. Common
resolutions are 96 and 120 DPI.
Apply that to your form, it should do the trick.
{enjoy}