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Scatter: new zoom and scroll mechanism! [message #28571]

Tue, 07 September 2010 16:39

tojocky
Messages: 607
Registered: April 2008
Location: UK

Contributor

Hello all,

I propose to change a little zoom and scroll mechanism:
1. scroll horizontal: When mouse (wheel) and the buttons "alt" "shift" and "ctrl" is not pressed
2. scroll vertical: when mouse (wheel) and is pressed the "alt" button
3. zoom horizontal proportional by mouse position: when mouse (wheel) and is pressed the "shift" button
4. zoom vertical proportional by mouse position: when mouse (wheel) and is pressed the "ctrl" button

The future: in the same time can zoom by X and Y axes by pressing "ctrl" "shift" and mouse wheel. The zoom is proportional by mouse position like google picassa and other photo viewers.

The code is:

void  Scatter::MouseWheel(Point p_point, int p_zdelta, dword p_other){
	double v_scale = p_zdelta/10000.;
	if(GetAlt()){
		SetXYMin(GetXMin(), GetYMin()+GetYRange()*v_scale, GetYMin2());
		SetMinUnits(GetXMinUnit(), GetYMinUnit()-GetYRange()*v_scale);
	}
	else{
		bool v_is_ctrl = GetCtrl();
		bool v_is_shift = GetShift();
		
		if(v_is_ctrl){ // zoom y
			double v_zoom_v = GetYRange()*v_scale;
			double v_mouse_pos_v = GetYByPoint(p_point) - GetYMin();
			if(v_mouse_pos_v>0){
				SetXYMin(GetXMin(), GetYMin()-v_zoom_v*v_mouse_pos_v/GetYRange(), GetYMin2());
			}
			SetRange(GetXRange(), GetYRange()+v_zoom_v, GetY2Range());
		}
		if(v_is_shift){ // zoom x
			double v_zoom_v = GetXRange()*v_scale;
			double v_mouse_pos_v = GetXByPoint(p_point) - GetXMin();
			if(v_mouse_pos_v>0){
				SetXYMin(GetXMin()-v_zoom_v*v_mouse_pos_v/GetXRange(), GetYMin(), GetYMin2());
			}
			SetRange(GetXRange()+v_zoom_v, GetYRange(), GetY2Range());
		}
		
		if(!((v_is_ctrl)||(v_is_shift))){
			SetMinUnits(GetXMinUnit()-GetXRange()*v_scale, GetYMinUnit());
			SetXYMin(GetXMin()+GetXRange()*v_scale, GetYMin(), GetYMin2());
		}
	}
	Refresh();
}

I'm waiting for your opinions.

If need, I can upload a compiled test-case

[Updated on: Tue, 07 September 2010 16:52]

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