[8] Review request for CR 8006406: lightweight embedding in other Java UI toolkits (original) (raw)

Jim Graham james.graham at oracle.com
Fri Feb 15 15:07:03 PST 2013

Thanks Anton,

I just noticed that the lines look pretty long. The JDK style guidelines indicate 80 character lines:

4.1 Line Length Avoid lines longer than 80 characters, since they're not handled well by many terminals and tools.

Note: Examples for use in documentation should have a shorter line length-generally no more than 70 characters.

Sorry not to have noticed or mentioned that earlier, if you fix the line lengths I don't think I need to review it any more...

        ...jim

On 2/15/13 1:56 AM, Anton V. Tarasov wrote:

Hi Jim,

I agree with the rest of your comments, fixed it. Here's the latest: http://cr.openjdk.java.net/~ant/8006406/webrev.8 http://cr.openjdk.java.net/~ant/8006406/javadoc.8 Thanks! Anton. On 2/15/13 3:56 AM, Jim Graham wrote: Great Anton,

Some spelling fixes. occures -> occurs {@code {i, j}} -> {@code (i, j)} (I usually use parens to encapculate coordinates, but maybe there are conventions in other places that use braces?) It might be good to put parens around the (0 <= i/j < width) formulas? But that would depend on how it looks in a browser and I didn't compile and javadoc the code to see that - if it looks fine without the parens then that's good. But, the description(s) look(s) good and accurate. Thanks! ...jim On 2/14/13 5:51 AM, Anton V. Tarasov wrote: Hi Jim,

On 2/14/13 6:26 AM, Jim Graham wrote: I've been busy with FX things, but I just got a chance to look at some of the new interfaces. Ok, thanks =)

Here are some (hopefully) minor comments:

LightweightContent: You never really define "image origin". The imageBufferReset() takes an x,y, but it doesn't state what those are referring to. Is that the x,y on the screen/scene where the image should be rendered to? Are they the values to use to figure out what the starting offset in the data array for the data for the image should be? One thing that would help would be to include a formula in the method comments that indicates how the data for pixels is retrieved from the buffer so there is no confusion, something like: ----- The {w} and {h} should match the width and height of the component returned from {getComponent()} with the pixel at the origin of the component, {(0, 0)} in the coordinate space of the component, appearing at {data[y * linestride + x]}. All indices {data[(y + j) * linestride + (x + i)]} where {0 <= i < w} and {0 <= j < h} will_ _represent valid pixel data for the component._ _-----_ _Did I interpret that correctly?_ _Yes, the formula is correct. I've put it into the doc:_ _/**_ _* {@code JLightweightFrame} calls this method to notify the client_ _application that a new data buffer_ _* has been set as a content pixel buffer. Typically this occures_ _when a buffer of a larger size is_ _* created in response to a content resize event. The method_ _reports a reference to the pixel data buffer,_ _* the content image bounds within the buffer and the line stride_ _of the buffer. These values have the_ _* following correlation._ _*

* The {@code width} and {@code height} matches the size of the content (the component returned from the * {@link #getComponent} method). The {@code x} and {@code y} is the origin of the content, {@code {0, 0}} * in the coordinate space of the content, appearing at {@code data[y * linestride + x]} in the buffer. * All indices {@code data[(y + j) * linestride + (x + i)]} where {@code 0 <= i < width} and {@code 0 <= j < height} * will represent valid pixel data, {@code {i, j}} in the coordinate space of the content. * * @param data the content pixel data buffer of INTARGBPRE type * @param x the x coordinate of the image * @param y the y coordinate of the image * @param width the width of the image * @param height the height of the image * @param linestride the line stride of the pixel buffer */ public void imageBufferReset(int[] data, int x, int y, int width, int height, int linestride); Is that enough clear now?

Then when you refer to xywh in imageReshaped I'm guessing it is just supplying 4 new parameters to replace the identical parameters that were in the Reset() method? That's right. There're three distinct events: buffer recreation (always or usually connected with new image bounds), image reshape (may not be connected to the first event) and image update (may not be connected to the first and second events). So, I thought all the three events should be reflected separately. Then in imageUpdated(), are the xywh relative to the coordinate system of the Component? Or are they in the same space as the original xywh were supplied to imageBufferReset? When you say they are "relative to the origin" I think you mean the former. The thing that makes it difficult to describe that is that you have the parameters to Reset and Reshape both named x,y and the parameters to Updated are also named x,y and one set of x,y parameters is relative to the other set and you end up having to say "The x and y are relative to the x and y". One of the sets of parameters should be renamed to make it easier to discuss how they relate. Some sort of "All indices in the range ..." statement would help to show how all of the numbers relate to each other. OK, I put it into the formula: /** * {@code JLightweightFrame} calls this method to notify the client application that a part of * the content image, or the whole image has been updated. The method reports bounds of the * rectangular dirty region. The {@code dirtyX} and {@code dirtyY} is the origin of the dirty * rectangle, which is relative to the origin of the content, appearing at * {@code data[(y + dirtyY] * linestride + (x + dirtyX)] in the pixel buffer * (see {@link #imageBufferReset}). All indices {@code data[(y + dirtyY + j] * linestride + * (x + dirtyX + i)]} where {@code 0 <= i < dirtyWidth} and {@code 0 <= j < dirtyHeight} * will represent valid pixel data, {@code {i, j}} in the coordinate space of the dirty rectangle. * * @param dirtyX the x coordinate of the dirty rectangle, relative to the image origin * @param dirtyY the y coordinate of the dirty rectangle, relative to the image origin * @param dirtyWidth the width of the dirty rectangle * @param dirtyHeight the height of the dirty rectangle * * @see #imageBufferReset * @see #imageReshaped */ public void imageUpdated(int dirtyX, int dirtyY, int dirtyWidth, int dirtyHeight); In SwingNode: Why is getContent() not just "return content;"? Actually, I had some more complicated construction there (wrapped content ref), in which I needed the local copy, then I reduced it, but missed the fact that it's even simpler now. Thanks for noticing, I'll fix it. Have you discussed the threading issues with anyone in FX? There is a big discussion right now on the appropriate threads for various activities... Not yet. I think we can start this discussion in the context of the review of the fx part (which actually does the threading stuff). Thanks, Anton.

...jim On 2/13/13 4:57 AM, Anton V. Tarasov wrote: Hi Sergey, new webrev: http://cr.openjdk.java.net/~ant/8006406/webrev.7 On 2/12/13 4:57 PM, Sergey Bylokhov wrote: Hi, Anton. Notes about implementation: 1 Seems some code was changed for debug simplifications or changes from previous implementations. It would be good to revert them back. (Ex /LWComponentPeer.bounds). Fixed all such occurrences (replaced with public "get" methods where available). Also, added "protected initializeBase(..)" method for field only initialization. 2 Probably it would be good to move grab/ungrab implementation from LWToolkit/WToolkit to SunToolkit? It looks unclear why we need so many grab/ungrab/grabFocus/ungrabFocus methods with the same implementation in the different places. We don't really need so much grabs and I will clean it when (and if) we publish the grab API. Please, see my replies to Anthony on this subject. 3 I suggest make all methods in LightweightFrame final if possible. Ok, I made toplevel related methods final. I'm not sure we should make final all the rest... (and by the way, the extender JLF class is final). 4 JLightweightFrame.rootPane could be final Did. 5 JLightweightFrame.getGraphics() probably graphics should be initialized by correct window fonts/background/foreground? Also when you create backbuffer probably it should be filled by background color? Note that if transparent images are supported you should be aware about composite. Ok, I did: 1) set transparent background for JLightweightFrame 2) set font/background/foreground for the Graphics. Now I think I shouldn't specially care about the composite (am I right?). 6 JLightweightFrame.initInterior you shouldn't dispose graphics. Yes, it seems this adheres to the javadoc: * Graphics objects which are provided as arguments to the * paint and update methods * of components are automatically released by the system when * those methods return. For efficiency, programmers should * call dispose when finished using * a Graphics object only if it was created * directly from a component or another Graphics object. Fixed it. 7 JLightweightFrame.reshape width * height could be changed to width | height ? No =) It rather could be changed to w & h, but in order not to confuse a reader, I've changed it to w == 0 || h == 0.

8 JLightweightFrame.reshape you did not flush old backbuffer. Did. Also, I had to override LWWindowPeer.updateCursorImmediately() in LWLFP to workaround the deadlock I faced on Mac. The deadlock has the following nature: - EDT: holding the paintLock (a shared lock b/w JLF and SwingNode), and the cursor manager dives to native code and tries to invoke a method on Main (FX App) thread. - FX Renderer: is about to render a SwingNode content, waiting on the paintLock. - FX App: (as far as I can guess) waiting for the Renderer to finish. I can start looking for the solution in parallel with the review, and if not yet found, I'd push the first patch with cursor updates disabled. Thanks! Anton. 08.02.2013 21:27, Anton V. Tarasov wrote: Hi All, Please, review the changes for the CR: http://bugs.sun.com/viewbug.do?bugid=8006406 webrev: http://cr.openjdk.java.net/~ant/8006406/webrev.6 It introduces sun.swing.JLightweightFrame class, aimed at lightweight embedding of Swing components into java-based toolkits. The primary target is JavaFX toolkit, however the class is not limited to this usage and the API it provides is quite generic. Below I'm giving a link to the jfx side implementation. This implementation should not be reviewed in this thread (it is in a pre-review phase), it should just clarify how the introduced API is supposed to be used. Namely, SwingNode.SwingNodeContent which implements sun.swing.LightweightContent and forwards requests from sun.swing.JLightweightFrame to NGExternalNode which does the rendering. webrev: http://cr.openjdk.java.net/~ant/RT-27887/webrev.1 Some comments on the awt/swing part: - Only Win and Mac implementation is currently available, X11 will come lately. - Win implementation uses a heavyweight window behind the lightweight frame, while it is not actually needed for lightweight embedding. This is due to the architecture of the Win AWT peers which are strongly tight to the native code, and it's not a trivial task to separate them. On Mac the lightweight frame peer is truly lightweight, meaning that it doesn't create an NSWindow object behind it. The Mac port LW abstraction allows to override and substitute CPlatform* classes with their lightweight stubs. - LightweightFrame, among others, introduces two new methods - grabFocus() and ungrabFocus(boolean). Ideally, these methods should go to the super Window class where the grab API becomes public (which is a long-term project...). Current host of the grab API is SunToolkit, which now forwards the calls to LightweightFrame. This is necessary to intercommunicate with the client when grab/ungrab happens on both sides. - Unresolved issues exist, like modal dialogs, d&d etc. They are to be addressed further. Thanks, Anton.

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