Mastering Sidebar Layouts in HarmonyOS Next

HarmonyOS Next offers powerful tools for crafting engaging user interfaces. This article delves into the SideBarContainer component, a key element for creating effective sidebar layouts that enhance user experience and navigation. We'll explore its functionality, demonstrate techniques for building scalable and adaptable sidebars, and showcase its integration with other components to achieve complex layouts like the popular three-column design.

The SideBarContainer Component: Your Sidebar Assistant

The SideBarContainer component acts as a foundation for building sidebars within your HarmonyOS Next applications. It's invaluable for apps with extensive content or features, such as file managers, music players, or settings panels, where a sidebar provides efficient navigation and access to various functions. Its simple yet flexible design allows for customization and seamless integration with other UI elements.

Implementing SideBarContainer is straightforward. Begin by importing the necessary library and then define the sidebar content within the component. Consider this example from a file management app:

import { SideBarContainer, SideBarContainerType } from '@ohos/sideBar';

@Entry
@Component
struct FileManagerSideBar {
    build() {
        SideBarContainer(SideBarContainerType.Embed) {
            Column() {
                Text('My Files').fontSize(20).fontWeight(500).padding(10)
                Text('Recently Used').fontSize(16).padding(10)
                Text('Favorites').fontSize(16).padding(10)
            }
              .backgroundColor('#F1F3F5')
        }
          .width('30%')
          .sideBarWidth('30%')
          .minSideBarWidth('20%')
          .maxSideBarWidth('50%')
          .showControlButton(true)
          .autoHide(false)
    }
}

This code creates an embedded sidebar with navigation options. Notice how properties like width, sideBarWidth, minSideBarWidth, maxSideBarWidth, showControlButton, and autoHide allow for precise control over sidebar behavior and appearance.

Building Scalable Sidebar Layouts

A truly user-friendly sidebar should adapt to the user's needs. Let's see how to create a scalable sidebar in HarmonyOS Next using the SideBarContainer component's properties:

@Entry
@Component
struct ScalableSideBar {
    @State isSideBarExpanded: boolean = true;
    build() {
        SideBarContainer(SideBarContainerType.Overlay) {
            Column() {
                // Sidebar content
                Text('Sidebar Content').fontSize(20).padding(10)
            }
              .backgroundColor('#19000000')
        }
          .sideBarWidth(this.isSideBarExpanded? '30%' : '10%')
          .minSideBarWidth('10%')
          .maxSideBarWidth('50%')
          .showControlButton(true)
          .autoHide(false)
          .showSideBar(this.isSideBarExpanded)
          .onChange((isOpen: boolean) => {
                this.isSideBarExpanded = isOpen;
            })
    }
}

Here, isSideBarExpanded controls the sidebar's width. The onChange callback dynamically updates the state based on user interaction with the control button, providing a smooth scaling effect. Remember to handle potential edge cases, such as screen size limitations, to prevent unexpected behavior.

Implementing a Three-Column Layout with Navigation

Three-column layouts are highly effective for large-screen applications. They typically consist of a sidebar for navigation, a list of options, and a main content area. In HarmonyOS Next, we combine SideBarContainer and the Navigation component to achieve this efficiently:

// ... (Route configuration and Page components - Page1.ets, Page2.ets, route_map.json omitted for brevity. See original draft for details.) ...

@Entry
@Component
struct TripleColumnLayout {
    @State arr: number[] = [1, 2];
    pageInfos: NavPathStack = new NavPathStack();
    @State arrSample: { label: string, pagePath: string }[] = [
        {
            label: 'Page 1',
            pagePath: 'Page1'
        },
        {
            label: 'Page 2',
            pagePath: 'Page2'
        }
    ];
    @Builder NavigationTitle() {
        Column() {
            Text('Sample Application').fontColor('#000000').fontSize(24).width('100%').height('100%').align(Alignment.BottomStart).margin({ left: '5%' })
        }
          .alignItems(HorizontalAlign.Start)
    }
    build() {
        SideBarContainer() {
            Column() {
                List() {
                    ForEach(this.arr, (item: number, index) => {
                        ListItem() {
                            Text('Side Navigation Item'+ item).width('100%').height("20%").fontSize(24).fontWeight(FontWeight.Bold).textAlign(TextAlign.Center).backgroundColor('#66000000')
                        }
                    })
                }
                  .divider({ strokeWidth: 5, color: '#F1F3F5' })
            }
              .width('100%')
              .height('100%')
              .justifyContent(FlexAlign.SpaceEvenly)
              .backgroundColor('#F1F3F5')
            Column() {
                Navigation(this.pageInfos) {
                    List() {
                        ForEach(this.arrSample, (item: { label: string, pagePath: string }, index) => {
                            ListItem() {
                                Text(item.label).fontSize(24).fontWeight(FontWeight.Bold).backgroundColor('#66000000').textAlign(TextAlign.Center).width('100%').height('30%').margin({ bottom: 10 }).onClick(() => {
                                    this.pageInfos.clear();
                                    this.pageInfos.pushPath({ name: item.pagePath });
                                })
                            }
                        })
                    }
                      .width('100%')
                }
                  .mode(NavigationMode.Auto)
                  .minContentWidth(360)
                  .navBarWidth(240)
                  .backgroundColor('#FFFFFF')
                  .height('100%')
                  .width('100%')
                  .hideToolBar(true)
                  .title(this.NavigationTitle)
            }
              .width('100%').height('100%')
        }
          .sideBarWidth(240)
          .minContentWidth(360)
    }
}

This example demonstrates a functional three-column layout. The SideBarContainer manages the sidebar, while the Navigation component handles the list and content areas. User clicks on sidebar and list items trigger navigation to the appropriate page. Careful consideration of responsiveness across different screen sizes is crucial for optimal user experience.

Conclusion

The SideBarContainer component in HarmonyOS Next provides a robust and flexible foundation for creating sophisticated sidebar layouts. By understanding its capabilities and combining it with other UI components, developers can craft intuitive and engaging user interfaces. Remember to prioritize responsive design and handle potential edge cases for a seamless user experience.