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To select multiple items, you repeatedly select single items using their checkboxes until all your items are selected (toggle selection). Alternatively, use a rubber band rectangle when using a mouse to select the items (object selection). Note that in the latter case, the checkboxes of all selected items are also checked as soon as you release the mouse button. A previously selected group of items is first deselected before the newly defined group becomes selected.
Select and deselect all items
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Views supporting the selection of multiple items shall also always offer an additional checkbox to toggle the selection of all items (visible or invisible) in the view. Checking it first selects all items, checking it again de-selects the items.
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