I have a THorzScrollBox in a form, and some TStyledControls inside. Each StyledControl has a Tag to identify. Using an TEdit to inform a value, I can find inside the ScrollBox an specific Control by his tag.
If the control that I searched is not on the screen, I want to scroll the ScrollBox to show it.
How can I do this programmatically?
I found a way to do this.
I have to use ScrollBy. But the detail is that if I want to scroll the controls to right I have to use a negative value.
Example:
sbItems.ScrollBy(-10, 0); // this will scroll to right
If I use a positive value, it will scroll to left.
sbItems.ScrollBy(10, 0); // this will scroll to left
The point is, if you scroll once, the ViewportPosition will change and the next time you execute ScrollBy, it will not reset the scroll position, it will scroll from the point you already have scrolled.
Related
The TDrawGrid component has a standard way of determining how much to scroll when you scroll to the right and left for example. I want the same behaviour as with a TScrollBox. The amount scrolled to the right and left is a lot less and you can control that. I was using a TScrollBox for this exact reason until I figured out that I can't have fixed Rows and Fixed Cols anymore because my ScrollBox determines the scrolling.
Is there a short way to do this without creating my own component?
I want to set center the content inside a UICollectionView according to ring image in the center of the whole screen. Please check the image below. Any Suggestions?
The function you need is this one... https://developer.apple.com/documentation/uikit/uicollectionviewdelegate/1618007-collectionview
This function is called by the collection view when the user finishes scrolling. It provides the content offset of where the collection view will stop scrolling. (The proposed content offset).
You then need to take that offset and work out the nearest offset to place your cell in the middle of the screen.
Something like, find the item that will be closest to the middle. Work out how far away from the middle it is so you know how much to shift it by. Then apply that shift to the proposed content offset.
This will allow your collection view to decelerate naturally but always stop at the point that you want it to stop.
In the previous version of Appium, I can use scroll functions to scroll to the particular element which is not visible on the screen.
My requirement is I have a Layout, in which many elements are there and that layout is scrollable. The element which I want to click is not visible on the screen and I have to scroll to a particular element and click that?
Can someone help me out on this issue how to scroll to the particular element?
In latest version of appium to scroll on the screen or to scroll the tables or to implement drag and drop functionalites we have to use TouchAction.
If we want to scroll in a scrollable layout first we have to get the bounds of that layout and give the coordinates in side that bounds.
Consider the below line of code.
new TouchAction(driver).press(300,200).moveTo(300,100).release().perform();
In this line of code we will perform the scroll down by 100 points.
.press(300,200) // Start at 300,200
.moveTo(0,100) // Increase Y by 300, ending up at 300,100
You have to pass the coordinates based on your requirements.
Find the details in below link:
https://appium.io/docs/en/writing-running-appium/touch-actions/
I have a readonly memo shwoing some text. However, there is a usability oddness. The user can pan the content in TMemo when only scroll ought to be possible.
Since people seem to think panning and scrolling is the same, I will give my definitions:
Panning = You can drag the entire content top/bottom/left/right (i.e. all
directions... NOT scrolling text but more like dragging entire "textview" object/widget. Also what is normally seen in image panning demos where you can pan the image in different directions to see e.g. top/bottom/left/right.)
Scrolling of text = scrolling of text the direction the content in the widget is placed (e.g. scrolling text up/down)
My question is how to only have scroll if possible. (And not be able to drag 2/3 of the entire text control out of the view although i bounces back when touch is let go)
What you are experiencing is an animation effect.
It can be turned off by setting the property:
AniCalculations.BoundsAnimation := false;
See FMX.InertialMovement.TAniCalculations.BoundsAnimation for more information.
I am using the VirtualTreeView together with the OnMeasureItem event to display rows of variable size. The problem is that the event seems to be called only if a row is painted (following the virtual paradigm). But this leads to the scrollbar being displayed incorrectly. If I scroll to the bottom (by dragging the scrollbox with the mouse, not clicking the scroll buttons at the top or bottom), not the last row is displayed (which is what I would expect), but some row in the middle. After that, the scrollbar is updated and I can scroll further down. It seems as if the component uses the DefaultNodeHeight for its scrolling calculations. But since my rows have variable height, I cannot specify a DefaultNodeHeight that would lead to correct results. Option toVariableNodeHeight is enabled.
Has anyone experienced this before and maybe found a workaround? Or am I doing it wrong?
You need to set DefaultNodeHeight to the maximum value you will be using and OnMeasureItem event set custom height value for the current node. Similar issue was described here.