Drawing lines on the screen


drawing on the screen

What MCU/Processor/Board and compiler are you using?


What LVGL version are you using?


What do you want to achieve?

I am making a notebook widget that has tabs and in order to make the widget flexible in it’s use for things like sizing the image I am using for the tabs needs to be completed by drawing a couple of lines. I do not know how to go about manually drawing the lines I need.

What have you tried so far?

Nothing yet as I do not even know where to begin.

Here is the image of the tab.


The black has an alpha channel of zero it’s not displaying properly on the forum. There are 2 colors that make the outside edge of the tab. I need to extend those lines on the bottom of each side of the tab to the edge of the parent object for the image. Below those lines will be an lv_obj instance that has the background set to the same blue used in the tab. The tab image and that object will be children of an lv_obj instance and positioned in a manner where the 2 pieces look like a single component. That parent “container” will have it’s background set to zero opacity. That coupled with the blank area on the tab and positioning of the tab in the parent will allow the tabs to layer on top of each other and still be visible. These “pages” will have an lv_obj instance as their parent and that parent will also have a child for each tab that is a transparent bar with transparent buttons as children. That will allow for registering touches to select which tab is to be viewed because that bar will be in the foreground and when a button is pressed the page/tab will get pulled to the foreground and then the button bar would get pulled to the foreground so it’s always on top.

It all works but I am using 5 separate images for 5 tabs with them each in a different location. The widget width is hard coded and doesn’t change. This is what I would like to change. I want to be able to have more than 5 tabs, more tabs than what could be seen on the screen and scrolling would allow for moving the viewable tabs. I need a way to render those lines in order for this to work properly.