ScrollPance moving with node Javafx - javafx

I have a scroll Pane with a rectangle inside the scroll Pane.The rectangle can only move left or right . The scroll pane has a with of 800,when the windows gets to small the scrollbar becomes enabled and you can scroll. My problem is when i try to move the rectangle when the scrollbar is on , the scroll bar will also move either left or right.Is the a way to temporary disable the scroll feature when i am moving the node >

I think what you might be looking for is
public final void setPannable(boolean value)
Sets the value of the property pannable.
Property description:
Specifies whether the user should be able to pan the viewport by using the mouse. If mouse events reach the ScrollPane (that is, if mouse events are not blocked by the contained node or one of its children) then pannable is consulted to determine if the events should be used for panning.
https://docs.oracle.com/javase/8/javafx/api/javafx/scene/control/ScrollPane.html#setPannable-boolean-
I'm not sure if this works, but sounds like it.
You also could use https://docs.oracle.com/javase/8/javafx/api/javafx/scene/Node.html#onMouseClickedProperty
or a similar MouseProperty, set up a Listener and make it so that when you click on the ScrollPane, it will set https://docs.oracle.com/javase/8/javafx/api/javafx/scene/control/ScrollPane.ScrollBarPolicy.html
to NEVER
public static final ScrollPane.ScrollBarPolicy NEVER
Indicates that a scroll bar should never be shown.
then back to your original setting for ScrollPane.onMouseReleased();
Good luck!

Related

Getting QScrollArea to resize its child widget immediately

I have a QScrollArea (we'll call it myContainer) that contains and scrolls a child view (we'll call it myChildWidget). All works almost fine - when I change the height of myChildWidget dynamically in response to something, if the height exceeds that of myContainer (the QScrollArea), a vertical scroll bar pops into view, effectively narrowing myChildWidget since I've set it to resize its child using:
myContainer->setWidgetResizable(true);
The problem is that myChildWidget is not actually resized until later, rather than right when I set its new height or try resizing myContainer, so I can't do certain things depending on its new width without subclassing and putting in a whole bunch of extra code. Surely there's something I can call to get the QScrollArea to auto-resize its child right away, right? I can use:
QCoreApplication::processEvents();
but the problem with that is that it causes the widgets to flash and redraw when I'm not done setting things up. I've tried update(), updateGeometry(), and adjustSize(), both on the container and its child, and none work. Anything I'm missing? Thanks for any help.

Scrolling QTableWidget smoothly

I have a QTableWidget with custom Widgets. These widgets are big and fill almost the whole scroll area in height, so that only one row is visible.
I can scroll with the mouse wheel or by dragging the scroll bar, but the row always jumps.
Is there a way to configure the QTableWidget to smoothly scroll, without jumping?
Try to use this:
view->setVerticalScrollMode(QAbstractItemView::ScrollPerPixel)
From Qt documentation:
enum ScrollMode { ScrollPerItem, ScrollPerPixel }
verticalScrollMode : ScrollMode
This property holds how the view scrolls its contents in the vertical
direction.
This property controls how the view scroll its contents vertically.
Scrolling can be done either per pixel or per item.

QListView Transparent Scrollbar with Image in QT

I am having QListWidget, i want to have a Transparent Scrollbar with Image.
Initially that scrollbar should be hidden on scroll only it should show.
How i Can achieve this in Qt ?
Any examples or ideas are welcomed.
How i can apply image to Listview Scrollbar.
Here are the three things you can look at to be able to control the scroll bar for most kinds of widgets in Qt:
VerticalScrollBarPolicy
HorizontalScrollBarPolicy
enum Qt::ScrollBarPolicy.
To be able to track how the user interacts with your QListWidget or any Widget for that matter you need to subclass it and implement the virtual methods from the QWheelEvent and possibly the QKeyEvent.
Scrolling is typically done with the mouse wheel and with the keyboard arrow keys and sometimes page-up and page-down and spacebar. I haven't done a lot with QListWidget, but you should double check which keyboard events/mouse events trigger scrolling.
These events will cause scrolling event even after you set either or both of the ScrollBarPolicies for the widget to be Qt::ScrollBarAlwaysOff.
First you should put in the constructor of your widget
this->setVerticalScrollBar(Qt::ScrollBarAlwaysOff);
this->setHorizontalScrollBar(Qt::ScrollBarAlwaysOff);
So you just need to setMouseTracking(true) for the widget (so that it tracks more than just the clicks) and reimplement at the very least wheelEvent(), and when a wheel event occurs, set the vertical/horizontal scroll bar policies to true and call update on your widget.
If you want to turn the scrollbars back off after a few milliseconds after they have started scrolling, you will need to create a QTimer in your constructor for your subclassed widget and connect it to a slot that sets the scroll bar polices on the timeout. Then you start/restart that timer every time the user does a wheelEvent().
As far as applying an image to the ListView Scrollbar, you should look into subclassing QAbstractScrollBar, if you want to actually put an image on it or change the way it looks. Setting up some tool buttons may also be the way to go if you are trying to put buttons with different icons in place of the scrollbar.

Flex Drag and Drop

I have an image that I show inside a canvas which I can zoom in on.
The problem is that when zoomed in, I try to drag the image, I can see the outline of the image in the foreground, (i.e.) outside the canvas boundary.
Is there anyway to tell the dragHandler to crop the "grabbed" image outside the canvas boundary?
In my experience using the built in drag/drop flex stuff is overkill for something that involves moving a component around in a canvas.
The easier way to do this (in my opinion) would be to listen for mouse down/up/move the image around in the canvas yourself.
When you detect a mouse down on your image, add a listener for mouse move (pro tip: make sure you set useCapture to true when calling addEventListener) and store the position of the mouse relative the origin of your image. Then whenever you get a mouse move, change the position of your image within your canvas taking into account the position of the mouse within the image (which you stored on mouse down). Keep doing this until mouse up occurs, then remove your mouse move listener.
There are some additional finer points to account for (what if the user drags outside of the canvas? Or outside of the browser window?), but this will get you started.
Hope that helps.

drag and drop in Canvas

I'm doing an application in flex where I draw different sprites inside a canvas. Depending of the dimensions, scrollbars can be appear. I would like to move the "image" with the movement of the mouse as you can see at the Adobe Reader when you are reading a document with zoom (hand mouse icon). In this way, you dont have to touch the scrollbar.
I'm start trying with drag and drop properties of the canvas, setting the position of the scrollbar according with the movement of the mouse but that is not as I expect.
Any ideas or suggestions?
Thanks in advance.
Recipe:
Listen for the mouseMove (MouseEvent.MOUSE_MOVE) event on the canvas
In event listener, examine event.localX, event.localY
Based on those values and the canvas's width and height, set the canvas's horizontalScrollPosition and verticalScrollPosition accordingly
Hope this helps.
What you can do is, change the position of the scrollbar , when the mouse reaches the last 20 pixels on the left or the right, or the top and bottom.
What you would really need to do is, have a mouseMove listener on the whole application, and when the mouse is within the end ranges of any of the sides, you can use the scroll.scrollTo function to move the scrollbars.

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