From 52824b85b53cd672033d600332d16e0bcc7fc0b7 Mon Sep 17 00:00:00 2001
From: Vadim Lopatin <buggins@fromru.com>
Date: Thu, 5 Jun 2014 14:11:09 +0400
Subject: [PATCH] grid: autohide scrollbars

---
 src/dlangui/widgets/controls.d | 19 +++++++++++++++++++
 src/dlangui/widgets/grid.d     | 29 ++++++++++++++++++++++++++---
 2 files changed, 45 insertions(+), 3 deletions(-)

diff --git a/src/dlangui/widgets/controls.d b/src/dlangui/widgets/controls.d
index 6ba32257..9c1d1d67 100644
--- a/src/dlangui/widgets/controls.d
+++ b/src/dlangui/widgets/controls.d
@@ -644,6 +644,24 @@ class ScrollBar : AbstractSlider, OnClickHandler {
         	layoutButtons();
     }
 
+    /// hide controls when scroll is not possible
+    protected void updateState() {
+        bool canScroll = _maxValue - _minValue > _pageSize;
+        if (canScroll) {
+            _btnBack.setState(State.Enabled);
+            _btnForward.setState(State.Enabled);
+            _indicator.visibility = Visibility.Visible;
+            _pageUp.visibility = Visibility.Visible;
+            _pageDown.visibility = Visibility.Visible;
+        } else {
+            _btnBack.resetState(State.Enabled);
+            _btnForward.resetState(State.Enabled);
+            _indicator.visibility = Visibility.Gone;
+            _pageUp.visibility = Visibility.Gone;
+            _pageDown.visibility = Visibility.Gone;
+        }
+    }
+
     protected void layoutButtons() {
         Rect irc = _scrollArea;
         if (_orientation == Orientation.Vertical) {
@@ -661,6 +679,7 @@ class ScrollBar : AbstractSlider, OnClickHandler {
             irc.right -= spaceForwardSize;
             layoutButtons(irc);
         }
+        updateState();
 	}
 
 	protected void layoutButtons(Rect irc) {
diff --git a/src/dlangui/widgets/grid.d b/src/dlangui/widgets/grid.d
index 0ea19e9c..4f5ebeb9 100644
--- a/src/dlangui/widgets/grid.d
+++ b/src/dlangui/widgets/grid.d
@@ -773,6 +773,15 @@ class StringGridWidget : GridWidgetBase, OnScrollHandler {
         //fnt.drawText(buf, rc.left, rc.top, "row"d, 0x000000);
 	}
 
+    Point fullContentSize() {
+        Point sz;
+        for (int i = 0; i < _cols; i++)
+            sz.x += _colWidths[i];
+        for (int i = 0; i < _rows; i++)
+            sz.y += _rowHeights[i];
+        return sz;
+    }
+
 	/// Measure widget according to desired width and height constraints. (Step 1 of two phase layout).
 	override void measure(int parentWidth, int parentHeight) { 
 		Rect m = margins;
@@ -786,7 +795,8 @@ class StringGridWidget : GridWidgetBase, OnScrollHandler {
 			pheight -= m.top + m.bottom + p.top + p.bottom;
 		_hscrollbar.measure(pwidth, pheight);
 		_vscrollbar.measure(pwidth, pheight);
-		measuredContent(parentWidth, parentHeight, 100, 100);
+        Point sz = fullContentSize();
+		measuredContent(parentWidth, parentHeight, sz.x, sz.y);
 	}
 
 	protected Rect _clientRect;
@@ -800,6 +810,15 @@ class StringGridWidget : GridWidgetBase, OnScrollHandler {
 		_needLayout = false;
 		applyMargins(rc);
 		applyPadding(rc);
+        Point sz = fullContentSize();
+        bool needHscroll = sz.x > rc.width;
+        bool needVscroll = sz.y > rc.height;
+        if (needVscroll)
+            needHscroll = sz.x > rc.width - _vscrollbar.measuredWidth;
+        if (needHscroll)
+            needVscroll = sz.y > rc.height - _hscrollbar.measuredHeight;
+        if (needVscroll)
+            needHscroll = sz.x > rc.width - _vscrollbar.measuredWidth;
 		// scrollbars
 		Rect vsbrc = rc;
 		vsbrc.left = vsbrc.right - _vscrollbar.measuredWidth;
@@ -809,10 +828,14 @@ class StringGridWidget : GridWidgetBase, OnScrollHandler {
 		hsbrc.top = hsbrc.bottom - _hscrollbar.measuredHeight;
 		_vscrollbar.layout(vsbrc);
 		_hscrollbar.layout(hsbrc);
+        _vscrollbar.visibility = needVscroll ? Visibility.Visible : Visibility.Gone;
+        _hscrollbar.visibility = needHscroll ? Visibility.Visible : Visibility.Gone;
 		// client area
 		_clientRect = rc;
-		_clientRect.right = vsbrc.left;
-		_clientRect.bottom = hsbrc.top;
+        if (needVscroll)
+		    _clientRect.right = vsbrc.left;
+        if (needHscroll)
+            _clientRect.bottom = hsbrc.top;
         updateScrollBars();
 	}