B4J Question Labels/Textfields: Any updates about measuring the width?

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KMatle

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This snippet works for me but it's just a workaround. Are there any updates about measuring the needed width to show the complete text (single line)?

Note: I need to use TextFields in a TableView to let the user edit the data fast.

B4X: 
Private Sub MeasureTextWidth (Text As String, Font As Font) As Float
  
    Dim lbl As Label
    lbl.Initialize("")
    lbl.Text = Text
    lbl.Font = Font
  
    MainForm.RootPane.AddNode(lbl, 0, 0, -1, -1) 'mBase is a B4XView panel.
    lbl.Snapshot
    lbl.RemoveNodeFromParent
    Return lbl.Width
End Sub
 
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Daestrum

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Not sure if this is accurate enough for you to use (it doesn't take into account font etc unless you set them)
B4X: 
Dim txt As JavaObject
...
 txt.InitializeNewInstance("javafx.scene.text.Text",Array(st)) ' st is the string to measure
 Log(txt.RunMethodJO("getLayoutBounds",Null).runmethod("getWidth",Null))
 
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stevel05

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Try this:
B4X: 
Private  Sub MeasureTexWidthNoWrap(Text As String,ThisFont As Font) As Double
    Dim TB,Bounds As JavaObject
    TB.InitializeStatic("javafx.scene.text.TextBuilder")
    Bounds = TB.RunMethodJO("create",Null).RunMethodJO("text",Array(Text)).RunMethodJO("font",Array(ThisFont)).RunMethodJO("build",Null).RunMethodJO("getLayoutBounds",Null)
    Return Bounds.RunMethod("getWidth",Null)
End Sub
 
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stevel05

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This looks promising and gives the same results as my first example, the applyCss method forces a layout pass on the Text object. From here : https://stackoverflow.com/questions/13015698/how-to-calculate-the-pixel-width-of-a-string-in-javafx

B4X: 
Private  Sub MeasureTexWidth(Text As String,ThisFont As Font) As Double

    Dim TextObj As JavaObject
    TextObj.InitializeNewInstance("javafx.scene.text.Text",Array(Text))
    TextObj.RunMethod("setFont",Array(ThisFont))
    TextObj.RunMethod("applyCss",Null)
    Dim Bounds As JavaObject
    Bounds = TextObj.RunMethodJO("getLayoutBounds",Null)
    Return Bounds.RunMethod("getWidth",Null)
End Sub
 
Last edited:
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Daestrum

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you may need to add the offsets in the textfield for an exact fit, but they are easy to get
B4X: 
asJO(tf).RunMethodJO("getInsets",Null).RunMethod("getLeft",Null) ' also getRight and add to width
 
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stevel05

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If you are still using Java 7 you will need to replace the applyCss call with

B4X: 
TextObj.RunMethod("snapshot",Array(Null,Null))
 
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