Last year, I embarked on a fascinating project involving one of my all-time favorite cartoon characters - the lasagna-loving cat, Garfield. My goal was to create an interactive digital collage, featuring various sizes of Garfield images on a screen, allowing for vertical scrolling.
Initially, I attempted this using Flow Row and Flow Column, but the results were not as expected. Fortunately, my mentor introduced me to the Lazy Staggered Grid in Jetpack Compose, which turned out to be a game-changer for my project. This experience led me to the discovery of the LazyVerticalStaggeredGrid and LazyHorizontalStaggeredGrid in Jetpack Compose.
These composables are designed for creating lazy-loaded, staggered grids of items. The LazyVerticalStaggeredGrid allows for a vertically scrollable layout with multiple columns, accommodating items of varying heights. Conversely, the LazyHorizontalStaggeredGrid operates similarly but on a horizontal axis, handling items of different widths.
Let’s delve into the specific sections of code: GridExample Composable Function This segment outlines the GridExample composable function, which establishes a staggered grid layout using the LazyVerticalStaggeredGrid.
This code can be accessed via this link:
https://gist.github.com/Starchild13/8075beb1f9b788f59c8d7aad0491c43e#file-photos-kt
Key components include:
Annotations:
•@OptIn(ExperimentalFoundationApi::class): This tag indicates reliance on the ExperimentalFoundationApi, signifying its experimental nature and potential for future changes.
Function Definition:
• @Composable fun GridExample(): This is the declaration of the GridExample composable function, responsible for emitting UI elements.
LazyVerticalStaggeredGrid:
• This creates a vertically scrolling grid.
• columns = StaggeredGridCells.Fixed(3): defines a three-column grid.
• modifier = Modifier.padding(8.dp): Sets an 8 dp padding around the grid.
Grid Items:
• items(getItems()) { drawable ->: Iterates over a list of drawable items from getItems().
• For each drawable, Image(...) displays the image with painter = painterResource(id = drawable) and modifier = Modifier.padding(4.dp) for padding.
getItems Function:
• This function returns a list of drawable resources, likely from the project's res/drawable folder. ChipItem Composable Function This part defines the ChipItem composable function, creating an interactive chip.
This section of code can be accessed via this link: https://gist.github.com/Starchild13/6107b45e9217f43d6a62e8e4422602d7#file-photos-kt.
Key components:
Annotations:
• @OptIn(ExperimentalMaterial3Api::class): Signals the use of the experimental ExperimentalMaterial3Api.
Function Definition:
• @Composable fun ChipItem(text: String, selected: MutableState): This composable function accepts a String and a MutableState as parameters.
FilterChip:
• Constructs a filter chip, a key UI element in Material Design.
• modifier = Modifier.padding(end = 16.dp): Applies end padding to the chip.
• selected = selected.value === text: The chip's selection status is based on whether its text matches the selected value.
• onClick = { selected.value = text }: Updates the selected state to the chip's text upon clicking.
• label = { Text(text)}: The chip displays the provided text as its label.
In conclusion, the “GridExample” function effectively showcases a staggered grid layout in a vertical, three-column arrangement using the “LazyVerticalStaggeredGrid” feature in Jetpack Compose, complete with image management and padding adjustments. Additionally, the “ChipItem” function serves as a practical example of creating an interactive filter chip, underlining the importance of mutable state management within the realm of composable functions. These functions together illustrate the power and flexibility of Jetpack Compose in building dynamic and responsive UI components for Android apps.