Application Techniques
Using Lists in a Window

A ListView control allows you to display items and icons in a variety of arrangements. You can display large icon or small icon freeform lists, or you can display a vertical static list. You can also display additional information about each list item by associating additional columns with each list item:

ListView controls consist of ListView items, which are stored in an array. Each ListView item consists of a:

For more information about ListView items, picture indexes, and presentation style, see the section called “ListView” in Users Guide.

Creating ListView controls

You add ListView controls to windows in the same way you add other controls: select ListView from the Insert>Control menu and click the window.

Adding ListView items

In the painter

Use the Items property page for the control to add items.

In a script

Use the AddItem and InsertItem functions to add items to a ListView dynamically at runtime. There are two levels of information you supply when you add items to a ListView using AddItem or InsertItem.

You can add an item by supplying the picture index and label, as this example shows:

lv_1.AddItem ("Item 1", 1)

or you can insert an item by supplying the item's position in the ListView, label, and picture index:

lv_1.InsertItem (1,"Item 2", 2)

You can add items by supplying the ListView item itself. This example in the ListView's DragDrop event inserts the dragged object into the ListView:

listviewitem lvi
This.GetItem(index, lvi)
lvi.label = "Test"
lvi.pictureindex = 1
This.AddItem (lvi)

You can insert an item by supplying the ListView position and ListView item:

listviewitem l_lvi
//Obtain the information for the
//second listviewitem
lv_list.GetItem(2, l_lvi)
//Change the item label to Entropy
//Insert the second item into the fifth position
lv_list.InsertItem (5, l_lvi)
lv_list.DeleteItem(2)

Adding pictures to ListView controls

PowerBuilder stores ListView images in four image lists:

You can associate a ListView item with these images when you create a ListView in the painter or use the AddItem and InsertItem at runtime.

However, before you can associate pictures with ListView items, they must be added to the ListView control.

In the painter

Use the Pictures and Items property pages for the control to add pictures.

In a script

Use the functions in the following table to add pictures to a ListView image.

Adding large and small pictures

This example sets the height and width for large and small pictures and adds three images to the large picture image list and the small picture image list:

//Set large picture height and width
lv_1.LargePictureHeight=32
lv_1.LargePictureWidth=32

//Add large pictures
lv_1.AddLargePicture("c:\ArtGal\bmps\celtic.bmp")
lv_1.AddLargePicture("c:\ArtGal\bmps\list.ico")
lv_1.AddLargePicture("Custom044!")

//Set small picture height and width
lv_1.SmallPictureHeight=16
lv_1.SmallPictureWidth=16

//Add small pictures
lv_1.AddSmallPicture("c:\ArtGal\bmps\celtic.bmp")
lv_1.AddSmallPicture("c:\ArtGal\bmps\list.ico")
lv_1.AddSmallPicture("Custom044!")

//Add items to the ListView
lv_1.AddItem("Item 1", 1)
lv_1.AddItem("Item 2", 1)
lv_1.AddItem("Item 3", 1)

Adding overlay pictures

Use the SetOverLayPicture function to use a large picture or small picture as an overlay for an item. This example adds a large picture to a ListView, and then uses it for an overlay picture for a ListView item:

listviewitem lvi_1
int li_index

//Add a large picture to a ListView
li_index = lv_list.AddLargePicture &
   ("c:\ArtGal\bmps\dil2.ico")

//Set the overlay picture to the
//large picture just added
lv_list.SetOverlayPicture (3, li_index)

//Use the overlay picture with a ListViewItem
lv_list.GetItem(lv_list.SelectedIndex (), lvi_1)
lvi_1.OverlayPictureIndex = 3
lv_list.SetItem(lv_list.SelectedIndex (), lvi_1)

Adding state pictures

This example uses an item's state picture index property to set the state picture for the selected ListView item:

listviewitem lvi_1

lv_list.GetItem(lv_list.SelectedIndex (), lvi_1)
lvi_1.StatePictureIndex = 2
lv_list.SetItem(lv_list.SelectedIndex (), lvi_1)

Deleting ListView items and pictures

You can delete items from a ListView one at a time with the DeleteItem function, or you can use the DeleteItems function to purge all the items in a ListView. Similarly, you can delete pictures one at a time with the DeleteLargePicture, DeleteSmallPicture, and DeleteStatePicture functions, or purge all pictures of a specific type by using the DeleteLargePictures, DeleteSmallPictures, and DeleteStatePictures functions.

This example deletes one item and all the small pictures from a ListView:

int li_index
li_index = This.SelectedIndex()
This.DeleteItem (li_index)
This.DeleteSmallPictures ()

Hot tracking and one- or two-click activation

Hot tracking changes the appearance of items in the Listview control as the mouse moves over them and, if the mouse pauses, selects the item under the cursor automatically. You can enable hot tracking by setting the TrackSelect property to TRUE.

Setting either OneClickActivate or TwoClickActivate to TRUE also enables hot tracking. When OneClickActivate is TRUE, you can specify that either selected or unselected items are underlined by setting the UnderlineHot or UnderlineCold properties. All these properties can be set on the control's general properties page or in a script.

The settings for OneClickActivate and TwoClickActivate shown in the following table affect when the ItemActivate event is fired.

Using custom events

In PowerBuilder 7 and later releases, PowerBuilder uses Microsoft controls for ListView and Treeview controls, and the events that fire when the right mouse button is clicked are different than in earlier releases. These are the events that fire when the right mouse button is clicked in a ListView control:

This.AddColumn("Name", Left!, 1000)
This.AddColumn("Size", Left!, 400)
This.AddColumn("Date", Left!, 300)

This.SetColumn (1, "Composition", Left!, 860)
This.SetColumn (2, "Album", Left!, 610)
This.SetColumn (3, "Artist", Left!, 710)

This.SetItem (1, 1, "St.Thomas")
This.SetItem (1, 2, "Saxophone Colossus")
This.SetItem (1, 3, "Sonny Rollins")
This.SetItem (2, 1, "So What")
This.SetItem (2, 2, "Kind of Blue")
This.SetItem (2, 3, "Miles Davis")
This.SetItem (3, 1, "Good-bye, Porkpie Hat")
This.SetItem (3, 2, "Mingus-ah-um")
This.SetItem (3, 3, "Charles Mingus")