<Swing Dev> [13] RFR JDK-8213535:Windows HiDPI html lightweight tooltips are truncated

[Prasanta Sadhukhan]

On 06-Apr-20 12:26 PM, Sergey Bylokhov wrote:
> On 4/5/20 11:08 pm, Prasanta Sadhukhan wrote:
>>
>> On 05-Apr-20 10:29 AM, Sergey Bylokhov wrote:
>>> On 4/2/20 8:59 pm, Prasanta Sadhukhan wrote:
>>>
>>>>> If we GC is correct in reset/pack step, but the View calculate 
>>>>> wrong size(and update it only after "graphicsConfiguration" 
>>>>> property change) means that we calculate the size of the View 
>>>>> using wrong GC, why?
>>>>
>>>> It's not the size of View, it's the preferredSize that is wrong. 
>>>> This is because tip's GC is null before the tip is shown, so View's 
>>>> span is calculated accordingly. Only when View isupdated when 
>>>> "graphicsConfiguration" is fired, then Tooltip GC is updated and 
>>>> preferredSpan is calculated correctly.
>>>>
>>>> It's to be remembered that the issue happens only when html text is 
>>>> shown in ToolTip. If normal text is shown , there is no issue. I 
>>>> guess if it's a question of wrong GC during popup reset/pack, then 
>>>> it will cause problem during normal text rendering also, no?
>>>
>>> If GC of the tip is null before showing then can we use default 
>>> screen GC by default? Same as in the java.awt.Window.initGC().
>>
>> I tried but SwingUtilities.windowForComponent(tip) returns null so 
>> there is no "Window" parent associated with tooltip so initGC() 
>> cannot be called on tip, as I see.
>>
>> Also, tip GC is null for normal text too, where it works. Only 
>> difference between normal and html text is in calculation of 
>> getPreferredSize/MaximumSize/MinimumSize where the size is updated 
>> based on updated span calculation, so I have used updated 
>> preferredSize in my fix.
>
> The normal text may work because the text and font metrics produce the 
> "correct" size which is not changed on the scaled screen, while the 
> HTML produce different size depending on the font metrics. Note that 
> you should not call Window.initGC() but use the similar logic 
> somewhere in the code which initialize/show tip.

I tried similar logic in ToolTipManager when the tip is created but to 
no effect. Even though BasicHTML.updateRenderer() is called but 
preferredSize is not updated, since JTooltip width/height was coming as 
0x0 in BasicToolTipUI#propertyChange()

              tip = insideComponent.createToolTip();
              tip.setTipText(toolTipText);
+
+            System.out.println("default gc " + gc.getDefaultTransform());
+            System.out.println("insideComponent GC " + 
insideComponent.getGraphicsConfiguration().getDefaultTransform());
+            GraphicsConfiguration oldConfig = 
tip.getGraphicsConfiguration();
+            System.out.println("tip oldgc " + 
tip.getGraphicsConfiguration());
+            GraphicsConfiguration newConfig = 
tip.getGraphicsConfiguration();
+            if (newConfig == null) {
+                newConfig = 
GraphicsEnvironment.getLocalGraphicsEnvironment().
+ getDefaultScreenDevice().getDefaultConfiguration();
+            }
+            System.out.println("newgc " + newConfig);
+            if (newConfig != null) System.out.println(" transform " + 
newConfig.getDefaultTransform());
+            tip.firePropertyChange("graphicsConfiguration", oldConfig, 
newConfig);
+
+
              size = tip.getPreferredSize();
+            System.out.println("tip preferredsize " + size);

              if(preferredLocation != null) {
                  location = toFind;

>
>