2.5: Buttons View

* When resizing the window, the top position is now preserved,
  instead of the center position.
* Fix zoom level not being preserved in various cases, when
  changing both with and height. This replaces some earlier code
  which did this at screen level but wasn't very reliable.
* Different tabs now each preserve their own scroll.
* When switching between tabs, it now scrolls to show as many
  buttons as possible, instead of possibly showing empty space.
  There is a trade-off here between doing that keeping the
  buttons in the same place, no ideal solution exists I think.
* Change zooming in/out to be symmetric, for example doing
  numpad + then - did not give the original zoom level back.
* Added some calls to avoid hanging tooltips when manipulating
  the view.

Internals:
* Added V2D_KEEPOFS_X and V2D_KEEPOFS_Y to keep the top/bottom
  rather than the center.
* Renamed V2D_KEEPZOOM to V2D_LIMITZOOM (seems more appropriate),
  and make V2D_KEEPZOOM preserve the zoom level.

2 files changed, 150 insertions, 33 deletions

diff --git a/source/blender/editors/interface/view2d.c b/source/blender/editors/interface/view2d.c
index c76110ac440..f9fb7a9306f 100644
--- a/source/blender/editors/interface/view2d.c
+++ b/source/blender/editors/interface/view2d.c
@@ -154,13 +154,15 @@ static void view2d_masks(View2D *v2d)
  */
 void UI_view2d_region_reinit(View2D *v2d, short type, int winx, int winy)
 {
-	short tot_changed= 0;
+	short tot_changed= 0, init= 0;
 	uiStyle *style= U.uistyles.first;
 
 	/* initialise data if there is a need for such */
 	if ((v2d->flag & V2D_IS_INITIALISED) == 0) {
 		/* set initialised flag so that View2D doesn't get reinitialised next time again */
 		v2d->flag |= V2D_IS_INITIALISED;
+
+		init= 1;
 		
 		/* see eView2D_CommonViewTypes in UI_view2d.h for available view presets */
 		switch (type) {
@@ -170,7 +172,7 @@ void UI_view2d_region_reinit(View2D *v2d, short type, int winx, int winy)
 			case V2D_COMMONVIEW_STANDARD:
 			{
 				/* for now, aspect ratio should be maintained, and zoom is clamped within sane default limits */
-				v2d->keepzoom= (V2D_KEEPASPECT|V2D_KEEPZOOM);
+				v2d->keepzoom= (V2D_KEEPASPECT|V2D_LIMITZOOM);
 				v2d->minzoom= 0.01f;
 				v2d->maxzoom= 1000.0f;
 				
@@ -197,7 +199,7 @@ void UI_view2d_region_reinit(View2D *v2d, short type, int winx, int winy)
 			case V2D_COMMONVIEW_LIST:
 			{
 				/* zoom + aspect ratio are locked */
-				v2d->keepzoom = (V2D_LOCKZOOM_X|V2D_LOCKZOOM_Y|V2D_KEEPZOOM|V2D_KEEPASPECT);
+				v2d->keepzoom = (V2D_LOCKZOOM_X|V2D_LOCKZOOM_Y|V2D_LIMITZOOM|V2D_KEEPASPECT);
 				v2d->minzoom= v2d->maxzoom= 1.0f;
 				
 				/* tot rect has strictly regulated placement, and must only occur in +/- quadrant */
@@ -214,7 +216,7 @@ void UI_view2d_region_reinit(View2D *v2d, short type, int winx, int winy)
 			case V2D_COMMONVIEW_STACK:
 			{
 				/* zoom + aspect ratio are locked */
-				v2d->keepzoom = (V2D_LOCKZOOM_X|V2D_LOCKZOOM_Y|V2D_KEEPZOOM|V2D_KEEPASPECT);
+				v2d->keepzoom = (V2D_LOCKZOOM_X|V2D_LOCKZOOM_Y|V2D_LIMITZOOM|V2D_KEEPASPECT);
 				v2d->minzoom= v2d->maxzoom= 1.0f;
 				
 				/* tot rect has strictly regulated placement, and must only occur in +/+ quadrant */
@@ -230,7 +232,7 @@ void UI_view2d_region_reinit(View2D *v2d, short type, int winx, int winy)
 			case V2D_COMMONVIEW_HEADER:
 			{
 				/* zoom + aspect ratio are locked */
-				v2d->keepzoom = (V2D_LOCKZOOM_X|V2D_LOCKZOOM_Y|V2D_KEEPZOOM|V2D_KEEPASPECT);
+				v2d->keepzoom = (V2D_LOCKZOOM_X|V2D_LOCKZOOM_Y|V2D_LIMITZOOM|V2D_KEEPASPECT);
 				v2d->minzoom= v2d->maxzoom= 1.0f;
 				v2d->min[0]= v2d->max[0]= (float)(winx-1);
 				v2d->min[1]= v2d->max[1]= (float)(winy-1);
@@ -257,9 +259,10 @@ void UI_view2d_region_reinit(View2D *v2d, short type, int winx, int winy)
 				float panelzoom= (style) ? style->panelzoom : 1.0f;
 				
 				/* for now, aspect ratio should be maintained, and zoom is clamped within sane default limits */
-				v2d->keepzoom= (V2D_KEEPASPECT|V2D_KEEPZOOM);
+				v2d->keepzoom= (V2D_KEEPASPECT|V2D_LIMITZOOM|V2D_KEEPZOOM);
 				v2d->minzoom= 0.5f;
 				v2d->maxzoom= 2.0f;
+				//tot_changed= 1;
 				
 				v2d->align= (V2D_ALIGN_NO_NEG_X|V2D_ALIGN_NO_POS_Y);
 				v2d->keeptot= V2D_KEEPTOT_BOUNDS;
@@ -298,17 +301,16 @@ void UI_view2d_region_reinit(View2D *v2d, short type, int winx, int winy)
 	
 	/* set 'tot' rect before setting cur? */
 	if (tot_changed) 
-		UI_view2d_totRect_set(v2d, winx, winy);
+		UI_view2d_totRect_set_resize(v2d, winx, winy, !init);
 	else
-		UI_view2d_curRect_validate(v2d);
-	
+		UI_view2d_curRect_validate_resize(v2d, !init);
 }
 
 /* Ensure View2D rects remain in a viable configuration 
  *	- cur is not allowed to be: larger than max, smaller than min, or outside of tot
  */
 // XXX pre2.5 -> this used to be called  test_view2d()
-void UI_view2d_curRect_validate(View2D *v2d)
+void UI_view2d_curRect_validate_resize(View2D *v2d, int resize)
 {
 	float totwidth, totheight, curwidth, curheight, width, height;
 	float winx, winy;
@@ -351,10 +353,30 @@ void UI_view2d_curRect_validate(View2D *v2d)
 	if(winx<1) winx= 1;
 	if(winy<1) winy= 1;
 	
-	/* keepzoom (V2D_KEEPZOOM set), indicates that zoom level on each axis must not exceed limits 
+	/* V2D_LIMITZOOM indicates that zoom level should be preserved when the window size changes */
+	if (resize && (v2d->keepzoom & V2D_KEEPZOOM)) {
+		float zoom, oldzoom;
+
+		if ((v2d->keepzoom & V2D_LOCKZOOM_X)==0) {
+			zoom= winx / width;
+			oldzoom= v2d->oldwinx / curwidth;
+
+			if(oldzoom != zoom)
+				width *= zoom/oldzoom;
+		}
+
+		if ((v2d->keepzoom & V2D_LOCKZOOM_Y)==0) {
+			zoom= winy / height;
+			oldzoom= v2d->oldwiny / curheight;
+
+			if(oldzoom != zoom)
+				height *= zoom/oldzoom;
+		}
+	}
+	/* keepzoom (V2D_LIMITZOOM set), indicates that zoom level on each axis must not exceed limits 
 	 * NOTE: in general, it is not expected that the lock-zoom will be used in conjunction with this
 	 */
-	if (v2d->keepzoom & V2D_KEEPZOOM) {
+	else if (v2d->keepzoom & V2D_LIMITZOOM) {
 		float zoom, fac;
 		
 		/* check if excessive zoom on x-axis */
@@ -460,11 +482,17 @@ void UI_view2d_curRect_validate(View2D *v2d)
 	if ((width != curwidth) || (height != curheight)) {
 		float temp, dh;
 		
-		/* resize from centerpoint */
+		/* resize from centerpoint, unless otherwise specified */
 		if (width != curwidth) {
 			if (v2d->keepofs & V2D_LOCKOFS_X) {
 				cur->xmax += width - (cur->xmax - cur->xmin);
 			}
+			else if (v2d->keepofs & V2D_KEEPOFS_X) {
+				if(v2d->align & V2D_ALIGN_NO_POS_X)
+					cur->xmin -= width - (cur->xmax - cur->xmin);
+				else
+					cur->xmax += width - (cur->xmax - cur->xmin);
+			}
 			else {
 				temp= (cur->xmax + cur->xmin) * 0.5f;
 				dh= width * 0.5f;
@@ -477,6 +505,12 @@ void UI_view2d_curRect_validate(View2D *v2d)
 			if (v2d->keepofs & V2D_LOCKOFS_Y) {
 				cur->ymax += height - (cur->ymax - cur->ymin);
 			}
+			else if (v2d->keepofs & V2D_KEEPOFS_Y) {
+				if(v2d->align & V2D_ALIGN_NO_POS_Y)
+					cur->ymin -= height - (cur->ymax - cur->ymin);
+				else
+					cur->ymax += height - (cur->ymax - cur->ymin);
+			}
 			else {
 				temp= (cur->ymax + cur->ymin) * 0.5f;
 				dh= height * 0.5f;
@@ -496,7 +530,7 @@ void UI_view2d_curRect_validate(View2D *v2d)
 		curheight= cur->ymax - cur->ymin;
 		
 		/* width */
-		if ( (curwidth > totwidth) && !(v2d->keepzoom & (V2D_KEEPZOOM|V2D_LOCKZOOM_X)) ) {
+		if ( (curwidth > totwidth) && !(v2d->keepzoom & (V2D_KEEPZOOM|V2D_LOCKZOOM_X|V2D_LIMITZOOM)) ) {
 			/* if zoom doesn't have to be maintained, just clamp edges */
 			if (cur->xmin < tot->xmin) cur->xmin= tot->xmin;
 			if (cur->xmax > tot->xmax) cur->xmax= tot->xmax;
@@ -542,13 +576,13 @@ void UI_view2d_curRect_validate(View2D *v2d)
 			 * We favour moving the 'minimum' across, as that's origin for most things
 			 * (XXX - in the past, max was favoured... if there are bugs, swap!)
 			 */
-			if ((cur->ymin < tot->ymin) && (cur->ymax > tot->ymax)) {
+			if ((cur->xmin < tot->xmin) && (cur->xmax > tot->xmax)) {
 				/* outside boundaries on both sides, so take middle-point of tot, and place in balanced way */
-				temp= (tot->ymax + tot->ymin) * 0.5f;
+				temp= (tot->xmax + tot->xmin) * 0.5f;
 				diff= curheight * 0.5f;
 				
-				cur->ymin= temp - diff;
-				cur->ymax= temp + diff;
+				cur->xmin= temp - diff;
+				cur->xmax= temp + diff;
 			}
 			else if (cur->xmin < tot->xmin) {
 				/* move cur across so that it sits at minimum of tot */
@@ -579,7 +613,7 @@ void UI_view2d_curRect_validate(View2D *v2d)
 		}
 		
 		/* height */
-		if ( (curheight > totheight) && !(v2d->keepzoom & (V2D_KEEPZOOM|V2D_LOCKZOOM_Y)) ) {
+		if ( (curheight > totheight) && !(v2d->keepzoom & (V2D_KEEPZOOM|V2D_LOCKZOOM_Y|V2D_LIMITZOOM)) ) {
 			/* if zoom doesn't have to be maintained, just clamp edges */
 			if (cur->ymin < tot->ymin) cur->ymin= tot->ymin;
 			if (cur->ymax > tot->ymax) cur->ymax= tot->ymax;
@@ -664,6 +698,11 @@ void UI_view2d_curRect_validate(View2D *v2d)
 	view2d_masks(v2d);
 }
 
+void UI_view2d_curRect_validate(View2D *v2d)
+{
+	return UI_view2d_curRect_validate_resize(v2d, 0);
+}
+
 /* ------------------ */
 
 /* Called by menus to activate it, or by view2d operators to make sure 'related' views stay in synchrony */
@@ -783,7 +822,7 @@ void UI_view2d_curRect_reset (View2D *v2d)
 /* ------------------ */
 
 /* Change the size of the maximum viewable area (i.e. 'tot' rect) */
-void UI_view2d_totRect_set (View2D *v2d, int width, int height)
+void UI_view2d_totRect_set_resize (View2D *v2d, int width, int height, int resize)
 {
 	int scroll= view2d_scroll_mapped(v2d->scroll);
 	
@@ -841,7 +880,57 @@ void UI_view2d_totRect_set (View2D *v2d, int width, int height)
 	}
 	
 	/* make sure that 'cur' rect is in a valid state as a result of these changes */
-	UI_view2d_curRect_validate(v2d);
+	UI_view2d_curRect_validate_resize(v2d, resize);
+}
+
+void UI_view2d_totRect_set(View2D *v2d, int width, int height)
+{
+	UI_view2d_totRect_set_resize(v2d, width, height, 0);
+}
+
+int UI_view2d_tab_set(View2D *v2d, int tab)
+{
+	float default_offset[2]= {0.0f, 0.0f};
+	float *offset, *new_offset;
+	int changed= 0;
+
+	/* if tab changed, change offset */
+	if(tab != v2d->tab_cur && v2d->tab_offset) {
+		if(tab < v2d->tab_num)
+			offset= &v2d->tab_offset[tab*2];
+		else
+			offset= default_offset;
+
+		v2d->cur.xmax += offset[0] - v2d->cur.xmin;
+		v2d->cur.xmin= offset[0];
+
+		v2d->cur.ymin += offset[1] - v2d->cur.ymax;
+		v2d->cur.ymax= offset[1];
+
+		/* validation should happen in subsequent totRect_set */
+
+		changed= 1;
+	}
+
+	/* resize array if needed */
+	if(tab >= v2d->tab_num) {
+		new_offset= MEM_callocN(sizeof(float)*(tab+1)*2, "view2d tab offset");
+
+		if(v2d->tab_offset) {
+			memcpy(new_offset, v2d->tab_offset, sizeof(float)*v2d->tab_num*2);
+			MEM_freeN(v2d->tab_offset);
+		}
+
+		v2d->tab_offset= new_offset;
+		v2d->tab_num= tab+1;
+	}
+
+	/* set current tab and offset */
+	v2d->tab_cur= tab;
+	v2d->tab_offset[2*tab+0]= v2d->cur.xmin;
+	v2d->tab_offset[2*tab+1]= v2d->cur.ymax;
+
+	return changed;
 }
 
 /* *********************************************************************** */
diff --git a/source/blender/editors/interface/view2d_ops.c b/source/blender/editors/interface/view2d_ops.c
index ee2a50d12a9..1e8cda68e6d 100644
--- a/source/blender/editors/interface/view2d_ops.c
+++ b/source/blender/editors/interface/view2d_ops.c
@@ -151,6 +151,7 @@ static void view_pan_apply(bContext *C, wmOperator *op)
 	/* request updates to be done... */
 	ED_area_tag_redraw(vpd->sa);
 	UI_view2d_sync(vpd->sc, vpd->sa, v2d, V2D_LOCK_COPY);
+	WM_event_add_mousemove(C);
 	
 	/* exceptions */
 	if(vpd->sa->spacetype==SPACE_OUTLINER) {
@@ -493,17 +494,33 @@ static void view_zoomstep_apply(bContext *C, wmOperator *op)
 {
 	ARegion *ar= CTX_wm_region(C);
 	View2D *v2d= &ar->v2d;
-	float dx, dy;
-	
-	/* calculate amount to move view by */
-	dx= (v2d->cur.xmax - v2d->cur.xmin) * (float)RNA_float_get(op->ptr, "zoomfacx");
-	dy= (v2d->cur.ymax - v2d->cur.ymin) * (float)RNA_float_get(op->ptr, "zoomfacy");
+	float dx, dy, facx, facy;
 	
+	/* calculate amount to move view by, ensuring symmetry so the
+	 * old zoom level is restored after zooming back the same amount */
+	facx= RNA_float_get(op->ptr, "zoomfacx");
+	facy= RNA_float_get(op->ptr, "zoomfacy");
+
+	if(facx >= 0.0f) {
+		dx= (v2d->cur.xmax - v2d->cur.xmin) * facx;
+		dy= (v2d->cur.ymax - v2d->cur.ymin) * facy;
+	}
+	else {
+		dx= ((v2d->cur.xmax - v2d->cur.xmin)/(1.0f + 2.0f*facx)) * facx;
+		dy= ((v2d->cur.ymax - v2d->cur.ymin)/(1.0f + 2.0f*facy)) * facy;
+	}
+
 	/* only resize view on an axis if change is allowed */
 	if ((v2d->keepzoom & V2D_LOCKZOOM_X)==0) {
 		if (v2d->keepofs & V2D_LOCKOFS_X) {
 			v2d->cur.xmax -= 2*dx;
 		}
+		else if (v2d->keepofs & V2D_KEEPOFS_X) {
+			if(v2d->align & V2D_ALIGN_NO_POS_X)
+				v2d->cur.xmin += 2*dx;
+			else
+				v2d->cur.xmax -= 2*dx;
+		}
 		else {
 			v2d->cur.xmin += dx;
 			v2d->cur.xmax -= dx;
@@ -513,18 +530,25 @@ static void view_zoomstep_apply(bContext *C, wmOperator *op)
 		if (v2d->keepofs & V2D_LOCKOFS_Y) {
 			v2d->cur.ymax -= 2*dy;
 		}
+		else if (v2d->keepofs & V2D_KEEPOFS_Y) {
+			if(v2d->align & V2D_ALIGN_NO_POS_Y)
+				v2d->cur.ymin += 2*dy;
+			else
+				v2d->cur.ymax -= 2*dy;
+		}
 		else {
 			v2d->cur.ymin += dy;
 			v2d->cur.ymax -= dy;
 		}
 	}
-	
+
 	/* validate that view is in valid configuration after this operation */
 	UI_view2d_curRect_validate(v2d);
-	
+
 	/* request updates to be done... */
 	ED_area_tag_redraw(CTX_wm_area(C));
 	UI_view2d_sync(CTX_wm_screen(C), CTX_wm_area(C), v2d, V2D_LOCK_COPY);
+	WM_event_add_mousemove(C);
 }
 
 /* --------------- Individual Operators ------------------- */
@@ -681,6 +705,7 @@ static void view_zoomdrag_apply(bContext *C, wmOperator *op)
 	/* request updates to be done... */
 	ED_area_tag_redraw(CTX_wm_area(C));
 	UI_view2d_sync(CTX_wm_screen(C), CTX_wm_area(C), v2d, V2D_LOCK_COPY);
+	WM_event_add_mousemove(C);
 }
 
 /* cleanup temp customdata  */
@@ -922,6 +947,7 @@ static int view_borderzoom_exec(bContext *C, wmOperator *op)
 	/* request updates to be done... */
 	ED_area_tag_redraw(CTX_wm_area(C));
 	UI_view2d_sync(CTX_wm_screen(C), CTX_wm_area(C), v2d, V2D_LOCK_COPY);
+	WM_event_add_mousemove(C);
 	
 	return OPERATOR_FINISHED;
 } 
@@ -1162,6 +1188,7 @@ static void scroller_activate_apply(bContext *C, wmOperator *op)
 	/* request updates to be done... */
 	ED_area_tag_redraw(CTX_wm_area(C));
 	UI_view2d_sync(CTX_wm_screen(C), CTX_wm_area(C), v2d, V2D_LOCK_COPY);
+	WM_event_add_mousemove(C);
 }
 
 /* handle user input for scrollers - calculations of mouse-movement need to be done here, not in the apply callback! */
@@ -1301,20 +1328,20 @@ static int reset_exec(bContext *C, wmOperator *op)
 		/* posx and negx flags are mutually exclusive, so watch out */
 		if ((v2d->align & V2D_ALIGN_NO_POS_X) && !(v2d->align & V2D_ALIGN_NO_NEG_X)) {
 			v2d->cur.xmax= 0.0f;
-			v2d->cur.xmin= v2d->winx*style->panelzoom;
+			v2d->cur.xmin= -winx*style->panelzoom;
 		}
 		else if ((v2d->align & V2D_ALIGN_NO_NEG_X) && !(v2d->align & V2D_ALIGN_NO_POS_X)) {
-			v2d->cur.xmax= (v2d->cur.xmax - v2d->cur.xmin)*style->panelzoom;
+			v2d->cur.xmax= winx*style->panelzoom;
 			v2d->cur.xmin= 0.0f;
 		}
 
 		/* - posx and negx flags are mutually exclusive, so watch out */
 		if ((v2d->align & V2D_ALIGN_NO_POS_Y) && !(v2d->align & V2D_ALIGN_NO_NEG_Y)) {
 			v2d->cur.ymax= 0.0f;
-			v2d->cur.ymin= -v2d->winy*style->panelzoom;
+			v2d->cur.ymin= -winy*style->panelzoom;
 		}
 		else if ((v2d->align & V2D_ALIGN_NO_NEG_Y) && !(v2d->align & V2D_ALIGN_NO_POS_Y)) {
-			v2d->cur.ymax= (v2d->cur.ymax - v2d->cur.ymin)*style->panelzoom;
+			v2d->cur.ymax= winy*style->panelzoom;
 			v2d->cur.ymin= 0.0f;
 		}
 	}
@@ -1325,6 +1352,7 @@ static int reset_exec(bContext *C, wmOperator *op)
 	/* request updates to be done... */
 	ED_area_tag_redraw(CTX_wm_area(C));
 	UI_view2d_sync(CTX_wm_screen(C), CTX_wm_area(C), v2d, V2D_LOCK_COPY);
+	WM_event_add_mousemove(C);
 	
 	return OPERATOR_FINISHED;
 }
@@ -1340,7 +1368,7 @@ void VIEW2D_OT_reset(wmOperatorType *ot)
 	ot->poll= view2d_poll;
 	
 	/* flags */
-	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO;
+	// ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO;
 }
  
 /* ********************************************************* */