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UIDefaults key?

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  UIDefaults key? Knute Johnson <eternal@knutejohnson.com> - 2014-08-06 09:25 -0700
    Re: UIDefaults key? Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-08-06 13:31 -0400
      Re: UIDefaults key? Knute Johnson <eternal@knutejohnson.com> - 2014-08-06 11:17 -0700
        Re: UIDefaults key? Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-08-06 14:38 -0400
          Re: UIDefaults key? Knute Johnson <eternal@knutejohnson.com> - 2014-08-06 13:00 -0700
            Re: UIDefaults key? Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-08-06 16:52 -0400

#29575 — UIDefaults key?

JComponent has a method, getUIClassID(),  to return the UIDefaults key 
for the ComponentUI subclass.  A JTextField returns a key of 
TextFieldUI.  A typical subclass is javax.swing.plaf.metal.MetalTextFieldUI.

All the interesting details in the UIDefaults however use keys such as 
TextField.foreground, TextField.border, TextField.margin etc.  Is there 
any way to get the prefix, TextField, from the component other than 
stripping the UI off the end of the UIClassID?

Thanks,

-- 

Knute Johnson

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#29576

On 8/6/2014 12:25 PM, Knute Johnson wrote:
> JComponent has a method, getUIClassID(),  to return the UIDefaults key
> for the ComponentUI subclass.  A JTextField returns a key of
> TextFieldUI.  A typical subclass is
> javax.swing.plaf.metal.MetalTextFieldUI.
>
> All the interesting details in the UIDefaults however use keys such as
> TextField.foreground, TextField.border, TextField.margin etc.  Is there
> any way to get the prefix, TextField, from the component other than
> stripping the UI off the end of the UIClassID?

     Climbing the class hierarchy from MetalTextFieldUI up to
BasicTextFieldUI, I find the method

     /**
      * Fetches the name used as a key to lookup properties through the
      * UIManager.  This is used as a prefix to all the standard
      * text properties.
      *
      * @return the name ("TextField")
      */
     protected String getPropertyPrefix() {
         return "TextField";
     }

... which sort of looks like what you're after.  (But I haven't
researched any other delegate classes, so it's possible they're
different.)

-- 
esosman@comcast-dot-net.invalid

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#29578

On 8/6/2014 10:31, Eric Sosman wrote:
> On 8/6/2014 12:25 PM, Knute Johnson wrote:
>> JComponent has a method, getUIClassID(),  to return the UIDefaults key
>> for the ComponentUI subclass.  A JTextField returns a key of
>> TextFieldUI.  A typical subclass is
>> javax.swing.plaf.metal.MetalTextFieldUI.
>>
>> All the interesting details in the UIDefaults however use keys such as
>> TextField.foreground, TextField.border, TextField.margin etc.  Is there
>> any way to get the prefix, TextField, from the component other than
>> stripping the UI off the end of the UIClassID?
>
>      Climbing the class hierarchy from MetalTextFieldUI up to
> BasicTextFieldUI, I find the method
>
>      /**
>       * Fetches the name used as a key to lookup properties through the
>       * UIManager.  This is used as a prefix to all the standard
>       * text properties.
>       *
>       * @return the name ("TextField")
>       */
>      protected String getPropertyPrefix() {
>          return "TextField";
>      }
>
> ... which sort of looks like what you're after.  (But I haven't
> researched any other delegate classes, so it's possible they're
> different.)
>

I think that is the answer Eric but I just not sure how to get there 
from here yet :-).

Thanks,

-- 

Knute Johnson

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#29579

On 8/6/2014 2:17 PM, Knute Johnson wrote:
> On 8/6/2014 10:31, Eric Sosman wrote:
>> On 8/6/2014 12:25 PM, Knute Johnson wrote:
>>> JComponent has a method, getUIClassID(),  to return the UIDefaults key
>>> for the ComponentUI subclass.  A JTextField returns a key of
>>> TextFieldUI.  A typical subclass is
>>> javax.swing.plaf.metal.MetalTextFieldUI.
>>>
>>> All the interesting details in the UIDefaults however use keys such as
>>> TextField.foreground, TextField.border, TextField.margin etc.  Is there
>>> any way to get the prefix, TextField, from the component other than
>>> stripping the UI off the end of the UIClassID?
>>
>>      Climbing the class hierarchy from MetalTextFieldUI up to
>> BasicTextFieldUI, I find the method
>>
>>      /**
>>       * Fetches the name used as a key to lookup properties through the
>>       * UIManager.  This is used as a prefix to all the standard
>>       * text properties.
>>       *
>>       * @return the name ("TextField")
>>       */
>>      protected String getPropertyPrefix() {
>>          return "TextField";
>>      }
>>
>> ... which sort of looks like what you're after.  (But I haven't
>> researched any other delegate classes, so it's possible they're
>> different.)
>>
>
> I think that is the answer Eric but I just not sure how to get there
> from here yet :-).

     Sorry: I somehow thought you already had your hands on an instance
of the ComponentUI subclass -- But now I think you've got nothing but a
JComponent object.  Also, I see that the method I stumbled upon is
defined for some ComponentUI subclasses, but not for all.

     Perhaps it's time to take a step back and think about the eventual
goal rather than about one particular (and possibly unworkable) route
toward it.  What problem are you trying to solve?

-- 
esosman@comcast-dot-net.invalid

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#29580

On 8/6/2014 11:38, Eric Sosman wrote:
> On 8/6/2014 2:17 PM, Knute Johnson wrote:
>> On 8/6/2014 10:31, Eric Sosman wrote:
>>> On 8/6/2014 12:25 PM, Knute Johnson wrote:
>>>> JComponent has a method, getUIClassID(),  to return the UIDefaults key
>>>> for the ComponentUI subclass.  A JTextField returns a key of
>>>> TextFieldUI.  A typical subclass is
>>>> javax.swing.plaf.metal.MetalTextFieldUI.
>>>>
>>>> All the interesting details in the UIDefaults however use keys such as
>>>> TextField.foreground, TextField.border, TextField.margin etc.  Is there
>>>> any way to get the prefix, TextField, from the component other than
>>>> stripping the UI off the end of the UIClassID?
>>>
>>>      Climbing the class hierarchy from MetalTextFieldUI up to
>>> BasicTextFieldUI, I find the method
>>>
>>>      /**
>>>       * Fetches the name used as a key to lookup properties through the
>>>       * UIManager.  This is used as a prefix to all the standard
>>>       * text properties.
>>>       *
>>>       * @return the name ("TextField")
>>>       */
>>>      protected String getPropertyPrefix() {
>>>          return "TextField";
>>>      }
>>>
>>> ... which sort of looks like what you're after.  (But I haven't
>>> researched any other delegate classes, so it's possible they're
>>> different.)
>>>
>>
>> I think that is the answer Eric but I just not sure how to get there
>> from here yet :-).
>
>      Sorry: I somehow thought you already had your hands on an instance
> of the ComponentUI subclass -- But now I think you've got nothing but a
> JComponent object.  Also, I see that the method I stumbled upon is
> defined for some ComponentUI subclasses, but not for all.
>
>      Perhaps it's time to take a step back and think about the eventual
> goal rather than about one particular (and possibly unworkable) route
> toward it.  What problem are you trying to solve?
>

I'm trying to find one of the properties, ???.background, for several 
different components.  Currently, I get the UIClassID from the component 
and lop of the UI at the end and use that as a key to get the value from 
UIDefaults.  I was hoping to find a way to get the UIDefaults key 
directly from the JComponent but I'm not having much luck.

That method you found is the way to go but I don't know how to get 
there.  I've got the name of the class, I just need to create an 
instance and call the getPropertyPrefix() method.

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.plaf.*;
import javax.swing.plaf.basic.*;

public class test9 {
     public static void main(String... args) {
         EventQueue.invokeLater(new Runnable() {
             public void run() {
                 JTextField tf = new JTextField();
                 String key = tf.getUIClassID();
                 System.out.println(key);
                 UIDefaults defaults = UIManager.getDefaults();
                 Class<? extends ComponentUI> clazz = 
defaults.getUIClass(key);
                 System.out.println(clazz.getName());
             }
         });
     }
}

-- 

Knute Johnson

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#29581

On 8/6/2014 4:00 PM, Knute Johnson wrote:
> On 8/6/2014 11:38, Eric Sosman wrote:
>> On 8/6/2014 2:17 PM, Knute Johnson wrote:
>>> On 8/6/2014 10:31, Eric Sosman wrote:
>>>> On 8/6/2014 12:25 PM, Knute Johnson wrote:
>>>>> JComponent has a method, getUIClassID(),  to return the UIDefaults key
>>>>> for the ComponentUI subclass.  A JTextField returns a key of
>>>>> TextFieldUI.  A typical subclass is
>>>>> javax.swing.plaf.metal.MetalTextFieldUI.
>>>>>
>>>>> All the interesting details in the UIDefaults however use keys such as
>>>>> TextField.foreground, TextField.border, TextField.margin etc.  Is
>>>>> there
>>>>> any way to get the prefix, TextField, from the component other than
>>>>> stripping the UI off the end of the UIClassID?
>>>>
>>>>      Climbing the class hierarchy from MetalTextFieldUI up to
>>>> BasicTextFieldUI, I find the method
>>>>
>>>>      /**
>>>>       * Fetches the name used as a key to lookup properties through the
>>>>       * UIManager.  This is used as a prefix to all the standard
>>>>       * text properties.
>>>>       *
>>>>       * @return the name ("TextField")
>>>>       */
>>>>      protected String getPropertyPrefix() {
>>>>          return "TextField";
>>>>      }
>>>>
>>>> ... which sort of looks like what you're after.  (But I haven't
>>>> researched any other delegate classes, so it's possible they're
>>>> different.)
>>>>
>>>
>>> I think that is the answer Eric but I just not sure how to get there
>>> from here yet :-).
>>
>>      Sorry: I somehow thought you already had your hands on an instance
>> of the ComponentUI subclass -- But now I think you've got nothing but a
>> JComponent object.  Also, I see that the method I stumbled upon is
>> defined for some ComponentUI subclasses, but not for all.
>>
>>      Perhaps it's time to take a step back and think about the eventual
>> goal rather than about one particular (and possibly unworkable) route
>> toward it.  What problem are you trying to solve?
>>
>
> I'm trying to find one of the properties, ???.background, for several
> different components.  Currently, I get the UIClassID from the component
> and lop of the UI at the end and use that as a key to get the value from
> UIDefaults.  I was hoping to find a way to get the UIDefaults key
> directly from the JComponent but I'm not having much luck.
>
> That method you found is the way to go but I don't know how to get
> there.  I've got the name of the class, I just need to create an
> instance and call the getPropertyPrefix() method.

     ... which (as I failed to notice), is `protected'.  Also, it's
not a ComponentUI method, but a method that some (most?) subclasses
happen to provide, independently of each other.

> import java.awt.*;
> import java.awt.event.*;
> import javax.swing.*;
> import javax.swing.plaf.*;
> import javax.swing.plaf.basic.*;
>
> public class test9 {
>      public static void main(String... args) {
>          EventQueue.invokeLater(new Runnable() {
>              public void run() {
>                  JTextField tf = new JTextField();
>                  String key = tf.getUIClassID();
>                  System.out.println(key);
>                  UIDefaults defaults = UIManager.getDefaults();
>                  Class<? extends ComponentUI> clazz =
> defaults.getUIClass(key);
>                  System.out.println(clazz.getName());
>              }
>          });
>      }
> }

     Here's a horrible hack that works for me, but it looks awfully
shaky (and shakily awful):

import java.awt.*;
import java.awt.event.*;
import java.awt.event.*;
import java.lang.reflect.*;
import java.util.logging.Level;
import javax.swing.*;
import javax.swing.*;
import javax.swing.plaf.*;
import javax.swing.plaf.*;
import javax.swing.plaf.basic.*;

public class test10 {

    public static void main(String... args) {
       EventQueue.invokeLater(new Runnable() {
          public void run() {
             JTextField tf = new JTextField();
             String key = tf.getUIClassID();
             System.out.println(key);
             UIDefaults defaults = UIManager.getDefaults();
             Class<? extends ComponentUI> clazz = defaults.getUIClass(key);
             System.out.println(clazz.getName());

             Method method = findIt(clazz);
             System.out.println(method.getName());
             method.setAccessible(true);

             try {
                Constructor ctor = clazz.getConstructor(null);
                System.out.println(ctor.getName());
                ComponentUI instance = (ComponentUI) ctor.newInstance(null);
                System.out.println(instance);
                String prefix = (String) method.invoke(instance, null);
                System.out.println("prefix = \"" + prefix + "\"! Huzzah!");
             } catch (Exception ex) {
                ex.printStackTrace();
             }
          }
       });
    }

    private static Method findIt(Class<?> clazz) {
       while (ComponentUI.class.isAssignableFrom(clazz)) {
          for (Method meth : clazz.getDeclaredMethods()) {
             if (meth.getName().equals("getPropertyPrefix")) {
                return meth;
             }
          }
          clazz = clazz.getSuperclass();
       }
       throw new IllegalStateException("no getPropertyPrefix!");
    }
}

     Filthy and fragile, no?

     Hmmm: If you're looking for the default background of a JDoodad in
the prevailing look and feel, how about constructing a JDoodad, doing
nothing special to it, and calling getBackground()?

-- 
esosman@comcast-dot-net.invalid

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