I'm making a grid of hexagons by placing Positioned Widgets. I have them inside an Interactive Viewer Widget so I can zoom in and out and move around.
Issue I'm having however is that with a large number of them being rendered it's far too laggy. It's unusable with about 4000 rendered on screen and ideally I need 10s of thousands. And this has nothing to do with the Widget itself as it's the same when replaced with a SizedBox with a Container or Text in.
I am using an InteractiveViewer.builder and only render the Widgets on the screen, which works great and there's no lag when zoomed in with few widgets on the screen, however I need to zoom out and see more.
I've also run in release mode and it's the same. I'm running in Windows and my PC is more than capable, too capable compared to the phones this should also be able to run on.
Is there some way to increase performance, or some other way I should be doing this instead of thousands of Positioned Widgets? Or is Flutter just not suited for this?
Edit: Image.
Using a widget for each individual hexagon at that scale feels like massive overkill. If you're going to use flutter, maybe use a CustomPaint widget, which allows you to draw shapes directly to a pixel grid?
You could wrap it in a GestureDector and implement scrolling and zooming via that perhaps?
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I am working on building a mobile application using flutter and am stuck on building a resposive login screen layout. To be precise, I am using the MediaQuery to find the screen size and to find the safe area and based on that I am spacing and building containers based on percentage of screen height. I would like to know if this is the best way or if I am unnecessarily complicating the entire process. I did come across a few youtube videos where most of them give random numbers but when I try doing that, my layout most often than not ends of overflowing!
So far, I have mostly done this with just mathematical calculations. i.e. I have stuck to calculating the available height (total height - safe area) and then built all my containers based on this height (including their spacing). But, I am struggling with getting the right font size and this constant struggle to balance the UI in both android and iOS setup is eating up most of my time.
I built hundreds of screens in Flutter. It is very rare that you need to use exact screen height for a layout. Most screens fall into one of the three categories:
There are too many elements to fit into a screen of any size.
In this case you wrap your layout in SingleChildScrollView widget that has a Column child, and then put all other widgets in that Column. Users scroll down to see all visible elements they need to see.
There are too many elements to fit into smaller screen sizes, but they fit into larger screens.
In this case you still wrap your layout in SingleChildScrollView widget. Then you make your layout look nice on larger screens, but users on smaller screens still have to scroll down. This is not ideal, but sometimes it's the right solution. Making design elements smaller on a small screen often makes it hard to use or even totally unusable. Plus, having various calculations related to a screen size in your layout logic makes it a nightmare to test your app: you have to test it on all sorts of screen sizes.
All design elements can fit into a small screen.
In this case you should use Flex widgets (like Column, Row, Spacer, Center, etc.) to create your layout. These widgets already have a logic for spacing their children in the available space (for example, using mainAxisAlignment and crossAxisAlignment properties in Column and Row).
There are also widgets that can take a specified percentage of a screen (or their parent widget), but I never use them. I can imagine situations where these widgets can be useful, but for the vast majority of designs using Flex layout is a better option that results in better looking screens.
If you post your design and the layout you came up with, we can point if there are ways to optimize it.
I am coding a website with Flutter. My layout uses "blocks" of vertical content laid within a SingleChildScrollView. They look like rectangles of content (with images, text, buttons, etc in them), taking up the whole screen horizontally, and the whole screen vertically.
Currently, whenever I move the screen size around (drag the web window to be different sizes) the website breaks. If I move it to be really small horizontally, I cannot fit in the content I need, if I move it to be small vertically I get overflow errors (and vice versa). This is because I am using MediaQuery.of(context).size.height/width to layout my website.
My rectangular blocks of "content" all have their same respective parent: Container(width: MediaQuery.of(context).size.width, height: MediaQuery.of(context).size.height) so they completely adjust everytime I move the window. Is there a better way to implement responsive web? Would it be better to just specify (for example) 620 pixels height for the Container and double.infinity for the width? And then somehow make everything fit inside not overflow/look weird? Also, when I drag the bottom of the web window nothing expands/grows properly because at that same time all my "content blocks" are all resizing their height because I am technically resizing the screen.
Finally, I've tried using BoxConstraints's minHeight, maxHeight, minWidth, and maxWidth, yet they don't seem to work and still produce the yellow/black overflow lines when testing in a webview. Huh?
Also, how would I get a bottom scrollbar to appear horizontally once my webview window is fully dragged close horizontally and half my content is cut off, but I still would like to see it. Would this be necessary? Or would another solution not need this? I'm not sure...
How are other people working around this and achieving this? I feel like I am doing this completely wrong. It shouldn't be this difficult.
(Also, using LayoutBuilder I have 2 additional builds for mobile/tablet when the screen width reaches less than 1100px)
A year has passed since last time I had to use flutter to build a little app for my firm. At that time MediaQuery was the trending way to create layouts ready for every screen size.
Today I am trying to build a simple layout like this one:
The part I am concerned about is the 3 circles in the middle. They have an icon and text inside and must be positioned at the positions seen in screen.
So, I have been investigating a bit how to create that part of the layout in a responsive way. I mean, that the circles are positioned at the correct position and size relative to the screen size and that the icon and text inside the circle are positioned and resized correctly too ,to avoid overflowing the circles.
Is the MediaQuery class still the only tool that can be used to build this kind of responsive layouts? Would you tackle this layout using a different method?
Yes MediaQuery is still heavily used, but Flutter has introduced some good widgets based on Orientation and Responsive Layouts:
OrientationBuilder - Builds different widget trees based on Orientation - For Example if the device is horizontal, you might see a Square instead of a Circle.
CustomMultiChildLayout - It can automatically decide how to size and position each child, as well as size the parent. Single widgets can be used CustomSingleChildLayout
Also when resizing text automatically I found Auto Size Text to be amazing
I know there are game/sprite engines written for Flutter, but my goal is to better understand painting and widgets, so I want to do this myself.
If I wanted a bunch of small widgets that could move around on a gameboard, what would be the best way to do this? Would I just create a box widget with fixed dimensions and have a bunch of children where I could control their position?
One example would be having a playing area with scrabble tiles that could be moved around. Or Tetris blocks falling. Different widgets that can be anywhere and that can be moved. I'm just looking for someone to point me in the right direction. Thanks.
You can draw custom shapes and lines using canvas in flutter and then animate them as flutter supports 60 frames per second. You need to understand customPaint very well. Here is a great demonstration of how to use customPaint to draw custom shapes.
https://medium.com/#rjstech/flutter-custom-paint-tutorial-build-a-radial-progress-6f80483494df
I am working on a game using GTK3 as a rendering technique (terrible idea, but it's a school project).
My gameobjects are made of Image widgets and are placed in a Fixed container. It's working pretty well, however when i move widgets beoynd right or bottom border, the window automatically grows along with it.
I want the window to stay at the sam size, event if widget leaves its area and becomes invisible. It works when i move widget past the upper or left border.
I tried using gtk_widget_set_vexpand and gtk_widget_set_hexpand. My window is set as not resizable (gtk_window_set_resizable).
Is there any way I can achieve this?
This isn't the right way to use GTK+. GTK+ is intended for laying out widgets in a GUI program.
There are better options for animating 2D elements. One that works with GTK+ natively is the Clutter library. You can also integrate SDL or OpenGL or something like that if you so choose.
That being said, you can also use GtkLayout instead of GtkFixed, or put the GtkFixed in a GtkScrolledWindow and hide the scrollbars and set the scroll policy to prevent scrolling. It's still technically misuse, and in fact GtkFixed (and possibly GtkLayout too but the docs don't say) is really not supposed to be used anymore unless absolutely necessary because it doesn't give you automatic support for tricky UI layout problems, but it doesn't have extra dependencies.