How can I add a little space to the last page?

[TarasBounty]

I have implemented my own controls placed on top of the pdfrx widget.

Stack( children: [ _PdfContent(), Positioned.fill( bottom: 20, child: Align( alignment: Alignment.bottomCenter, child: _Controls(), ), ) ], )

The problem is that on the last page my controls are overlapping the PDF content. Is it possible to add a padding on the last page only?

@espresso3389

[TarasBounty]

Or not space, any widget.Using current version it's only possible to display any widget over the page, but I want smith like Column() widget behaviour or padding to page.

[espresso3389]

For extra paddings, you can use PdfViewerParams.layoutPages to add extra paddings on the bottom:

PdfViewerParams(
  layoutPages: (pages, params) {
    final width =
          pages.fold(0.0, (w, p) => max(w, p.width)) + params.margin * 2;
  
    final pageLayout = <Rect>[];
    var y = params.margin;
    for (int i = 0; i < pages.length; i++) {
      final page = pages[i];
      final rect =
          Rect.fromLTWH((width - page.width) / 2, y, page.width, page.height);
      pageLayout.add(rect);
      y += page.height + params.margin;
    }

    // extra padding on the bottom
    const extra = 100.0;
    return PdfPageLayout(
      pageLayouts: pageLayout,
      documentSize: Size(width, y + extra),
    );
  },
),

[espresso3389]

The code above does not take the zoom into consideration.
If you also reflect the zoom ratio, you can use controller to obtain the zoom ratio.

[TarasBounty]

I don't need to recalculate it everytime, I need only initial zoom. If I've tried to get initial zoom, controller returns Error: Unexpected null value.

[espresso3389]

Even though you don't need calculation on every zoom change, you should do that. It is needed to keep the internal consistency.

PdfViewerParams(
  layoutPages: (pages, params) {
    final controller = ... // from somewhere
    final zoom = controller.isReady ? controller.zoom : 1.0;
    final width =
          pages.fold(0.0, (w, p) => max(w, p.width)) + params.margin * 2;
  
    final pageLayout = <Rect>[];
    var y = params.margin;
    for (int i = 0; i < pages.length; i++) {
      final page = pages[i];
      final rect =
          Rect.fromLTWH((width - page.width) / 2, y, page.width, page.height);
      pageLayout.add(rect);
      y += page.height + params.margin;
    }

    // extra padding on the bottom
    const extra = 100.0;
    return PdfPageLayout(
      pageLayouts: pageLayout,
      documentSize: Size(width, y + extra / zoom),
    );
  },
),

[TarasBounty]

idk what I did wrong, but layoutPages is not called everytime I change zoom via .zoomUp() /.zoomDown()

Also, it called only one time when page rendering and final zoom = controller.isReady ? controller.currentZoom : 1.0; controller.isReady alsways return false, so zoom is always 1 but actually not =(

[espresso3389]

Woops, I'm wrong... :(
OK, so layoutPages does not help you.
I should think more about another mechanism to support your case.

[TarasBounty]

@espresso3389 any ideas?

[espresso3389]

The blocker behind the issue is that the room on the bottom is affected by zoom ratio.
If we simply place some widget or blank space around the pages, it is zoomed.

In my understanding, you want to place some fixed size margin on the bottom of the last page. Is it correct?

[TarasBounty]

Yes, it is

[TarasBounty]

Do you have an idea how to deal with it? I still need it ;-)

[TarasBounty]

I still need it..

[espresso3389]

Yes, I understood that!

[espresso3389]

@TarasBounty
1.0.70 contains an update for the issue that calls layoutPages for every zoom change. Please evaluate it and give me any feedback.

[TarasBounty]

Everything works perfectly now, thanks!
One note: previously (on v 1.0.65) my pdf content fills all available space on Web, with 1.0.70 it now renders with grey margins left and right.