The Progress Bar - DevExpress XPF Blog

This post summarizes the new features that will be introduced in the ExpressQuantumTreeList Suite v5, our tree list component for VCL. Many of the features presented here were introduced as a result of end-user feedback. For reference purposes, we’ve included the appropriate Support Center ID in parenthesis.

New Features and Enhancements (Click on an item to learn more):

• Performance Improvements
• Easy Migration
• New Layout Capabilities
• New Summary Options
• Built-in Context Menus
• Check Groups
• Design-Time Experience
• Other Minor Enhancements

 

Version 5 includes a new data access architecture which significantly improves performance when using data-aware TreeList controls. To reduce the number of time-consuming round trips, data is cached and modified bypassing the data controller. The data controller is only used to perform data store updates and to obtain notifications about external data store changes.

The ExpressQuantumTreeList version 5 provides implicit streaming compatibility with version 4. Therefore, legacy data formats don’t require additional conversions when migrating to the new version.

• Nested Bands (A1723) – The ExpressQuantumTreeList v5 now allows you to nest bands within other bands.

• Customizable Location of Expand Buttons (DS37880) – You can now specify which band displays expand buttons.

• Quick Band Visibility Customization (CS13535) – Similar to the feature introduced in the ExpressQuantumGrid v5, band visibility can now be easily changed, both at design and runtime via a specially designed dropdown list.

• Quick Column Visibility Customization (CS13535) – Just like bands, column visibility can now be changed via a specially designed dropdown list.

• Capability to specify multiple fixed bands – You are no longer limited to one fixed band on each side of the TreeList control.
• Customizable Layout Persistence – As with the ExpressQuantumGrid and ExpressPivotGrid, the ExpressQuantumTreeList allows you to specify how tree list, band and column properties are persisted to external data stores via specially designed events.
• These events enable you to:
  • Customize a list of properties to be saved (OnGetStoredProperties).
  • Provide property values to be saved to and restored from a data store (OnGetStoredPropertyValue and OnSetStoredPropertyValue).
  • Initialize columns that are created during the restoring process (OnInitStoredObject).

• Group Summaries (AS4414) – The ExpressQuantumTreeList v5 allows you to calculate summaries based on groups of nodes with the same parent. These summaries are displayed within group footers that can be optionally switched off.

• Multiple Summaries – You can now display multiple summaries per column in the footer and group footers.

• Ability to choose the calculation base for summary values – You can include all child nodes for the calculation base or calculate using only the immediate child nodes.

With v5, end-users can easily customize summary options using built-in context menus (see the Footer Context Menu and Group Footer Context Menu below).

• Column Header Context Menu – Allows end-users to change or apply various column options and specify the visibility of the footer and customization form.

• Footer Context Menu – Allows end-users to specify the required summary types, adjust the calculation base or disable summary calculation for footer cells.

• Group Footer Context Menu – Allows end-users to specify the required summary types, adjust the calculation base or disable summary calculation for group footer cells.

You can handle menu item clicks within built-in menus and display a custom menu (TPopupMenu descendant) rather than the built-in menu.

With v5, you can easily introduce check groups to your unbound tree lists. For each node you can specify which type of a control will be used to indicate the check state of the node’s immediate child nodes – check box or radio button. A parent node keeps track of child node states, and automatically updates its state, and vice versa. You can customize the default logic by handling a specially designed event. Also, you can optionally display the grayed state in parent nodes, or prohibit end-users from changing a node’s state.

With v5, you can access summary item properties by clicking the corresponding footer and group footer cells.

• Easily customizable node height (A72, DS13894) – Users can adjust the height of individual nodes. You can also specify the default height for all nodes in pixels.

• Easily customizable band heights – You can specify the exact band height in pixels. End-users can modify a band’s height by dragging its bottom edge.
• Capability to display overlay images over node and state images (DS2409). To accomplish this, do the following:
  • Add overlay images into the Images and StateImages image collections.
  • Assign a node’s OverlayIndex and OverlayStateIndex properties. At design time, you can assign these properties via the Items Editor.
  • To dynamically specify overlay image indexes, handle the TreeList control’s OnGetNodeImageIndex event. Within an OnGetNodeImageIndex event handler, check the AIndexType parameter for tlitOverlayIndex and tlitOverlayStateIndex values and pass overlay image indexes via the AIndex parameter.

• Capability to dynamically provide image lists for node and state images. This allows you to have nodes with different image sizes.

• Capability to provide or update values for virtual tree lists by handling specially designed events (S18306).
• Capability to optionally hide state images for non-focused nodes.
• Capability to respond to node focus and node selection (A871).