More findings (and questions): I am considering the case when StyleableTextField useTightTextBound=true (regular r/o labels):
1) getPreferredBoundsHeight() returns tightTextHeight (which is basically the pixel height of "T" for single line text, and top pixel to baseline of last line for multineline ) The comment says " This is the height used for positioning text according to its baseline" - I think that is OK for text with no descent (such as "Table") but not if text that has descent (ex "Expected"). In doubt, I would take the higher measure, not the lower one, to make sure no clipping occurs. 2) getLayoutBoundsHeight() returns height - (measuredTextSize.y - tightTextHeight) The comment says: // we want to return the text field height without the top and bottom offsets // (measuredTextSize.y - tightTextHeight) gives us the sum of top and bottom offsets - The first comment makes sense (height without offsets). But the calculation really does not make sense to me !?! IMO, both functions should return the same value, that is the height from the top pixel to the bottom pixel of the text, majored to make sure no clipping occurs. It should simply be: tightTextHeight + metrics.descent what do you think ? Maurice -----Message d'origine----- De : Maurice Amsellem [mailto:maurice.amsel...@systar.com] Envoyé : dimanche 23 février 2014 20:37 À : dev@flex.apache.org Objet : RE: Need your help on problem with opaqueBackground >I agree that the logic may need fixing. It may not have been tested at >large font sizes Yes. In fact, for small enough fonts, the measuring/layout computations approximations were somehow compensated by big enough paddings. I have seen that useTightTextBound=true is for regural text and useTightTextBound=false for editable text (TextArea, TextInput). So I will focus on the case where useTightTextBound = true, to minimize the impact. This will probably break some Mustella mobile tests. Maurice -----Message d'origine----- De : Alex Harui [mailto:aha...@adobe.com] Envoyé : dimanche 23 février 2014 20:10 À : dev@flex.apache.org Objet : RE: Need your help on problem with opaqueBackground I agree that the logic may need fixing. It may not have been tested at large font sizes. IIRC, tight text bounds tries to ignore the "gutter" around the textfield. There is always a few more pixels in the TextField around the actual text. -Alex ________________________________________ From: Maurice Amsellem [maurice.amsel...@systar.com] Sent: Sunday, February 23, 2014 10:25 AM To: dev@flex.apache.org Subject: RE: Need your help on problem with opaqueBackground The 15% was an empirical finding based on comparing "unscaledHeight" and the apparent physical height in pixels of the renderered item. So let's forget this for a moment, as I don't know where it comes from. Searching more, I found something else: StylableTextField has "useTightTextBounds=true", which is logical, as we want precise measurement. In the measure() function of IconItemRenderer, the preferred height of the text is retrieved by calling : STF.getPreferredBoundHeight() which returns, in this case , tightTextHeight (let's say 36 in our example). So one would think that when the STF is sized in layoutContents(), using the same value, the text will get the same height: layoutContents() labelDisplay. setLayoutBoundsSize ( width, 36). But in StylableTextField. setLayoutBoundsSize(), there is some logic regarding useTightTextBounds And at the end it set text.height = 63 !! (instead of 36). I don't know if SFT. setLayoutBoundSize (STF.getPreferredWidth() , STF.getPreferredBoundHeight) should be a no-op, I wonder if this logic needs to be reviewed ?? Line 1687 and follows: if (useTightTextBounds) { if (newHeight > 0) { var bottomOffset:Number = measuredTextSize.y - tightTextTopOffset - tightTextHeight; // when clipping, allow gutter to be outside of height // use 2x gutter (actual gutter is not part of tight text height) // when newHeight==1, actual visible height==3 (1px + 1x gutter) if (newHeight < tightTextHeight) bottomOffset = StyleableTextField.TEXT_HEIGHT_PADDING; // re-add the top and bottom offsets. (measuredTextSize.y - tightTextHeight) gives us // the sum of top and bottom offsets newHeight += (tightTextTopOffset + bottomOffset); } } this.height = newHeight; Maurice -----Message d'origine----- De : Alex Harui [mailto:aha...@adobe.com] Envoyé : dimanche 23 février 2014 17:45 À : dev@flex.apache.org Objet : RE: Need your help on problem with opaqueBackground The TextField extent is surprising to me. What does it mean to be 15% larger? What does transform.pixelbounds show? Does it have to do with the border or background property? -Alex ________________________________________ From: Maurice Amsellem [maurice.amsel...@systar.com] Sent: Sunday, February 23, 2014 5:20 AM To: dev@flex.apache.org Subject: Need your help on problem with opaqueBackground Hi team, Piotr has raised an interesting issue in mobile apps: https://issues.apache.org/jira/browse/FLEX-34107 When using a large font (size > 40) with IconItemRenderer on spark List, the bottom separators between items are not displayed. After some hours of debugging, I finally found the cause, but don't know how to fix it, because it's related to AIR. Here is the story, in short (details in the ticket): - Mobile item renderers "opaqueBackground=color" property draws an opaque background behind item renderers, to make scrolling faster (no transparency). - When StyleableTextField (text used in mobile renderers, inheriting from TextField) is given WxH size in flex, its actual extent will be around 15% larger - the opaqueBackground extent of a renderer (DisplayObject) is computed based on the cumulated extents of its children, not of its own width and height In LabelItemRenderer, the padding around the renderer is big enough (16 px at 160 DPI) to compensate for this excess size for fonts not too large However, in IconItemRender, the padding is set to 8px, so when the font size > 50, opaqueBackgorund overflows the item render size, and separator lines are masked. There are many ways of fixing this : - increase the padding in IconItemRenderer, for 'reasonable' font sizes - modify the measure() to account for the excess size, so that opaqueBackground never overflows. - etc... What do you think ? Maurice
