- Guidelines for hacking SWF
- ==========================
+ Guidelines for hacking SWF
+ ==========================
This document describes some of the minimal coding guidelines
to be followed while hacking the new SWF implementation. These
1. Please refer to the design document of SWF to understand the
implementation.
-2. Please follow the general coding style described for Mono project.
- /cvs/mono/docs/README (location ??)
+2. Please follow the general coding style described for the Mono
+ project (/cvs/mcs/class/README).
3. Method stubbing is highly discouraged. It's recommended to submit
an implemented method instead of just the signature. If you have
- to stub a property or method, please use the [MonoTODO("what")]
+ to stub a property or method, please use the [MonoTODO ("what")]
attribute to document what still needs to be done.
4. When you implement the drawing method for a control in a theme, it
should make call to ControlPaint class methods and System.Drawing
- classes. If it is not possible to implment a control's draw method
+ classes. If it is not possible to implement a control's draw method
under these restrictions and you need some functionality from
XplatUIDriver, please let us know. We will try to enhance the
driver, if *really* required.
-5. As mentioned in the design doc also, double buffering must be used
- by any new controls being added. Whenever a property or method that
- changes the look of the control is called, the bitmap representing
- the control should be updated. The Paint method should only copy
- the bitmap to the screen, and *not* recalculate or paint the control.
- To aid in double-buffering, the Control class provides the
- Control.DeviceContext and Control.ImageBuffer properties.
+5. Minimize redraws as much as possible by utilizing the clipRectangle
+ when possible.
- A typical OnPaint will look like this:
-
- protected override void OnPaint(PaintEventArgs pevent) {
- if (NeedRedraw) {
- Redraw();
- }
-
- pevent.Graphics.DrawImage(this.ImageBuffer,
- pevent.ClipRectangle,
- pevent.ClipRectangle,
- GraphicsUnit.Pixel);
- }
-
- The ImageBuffer bitmap is supposed to contain the representation
- of the control, often drawn when a property is set, similar to this:
-
- public Color RectColor {
- set {
- sb.Color = value;
- NeedRedraw = true;
- }
- }
-
- internal void Redraw() {
- this.DeviceContext.FillRectangle(sb, this.ClientRectangle);
- }
-
-
-6. Minimize redraws as much as possible by setting a flag when a redraw
- is required and calling the redraw code once when painting. (See #5
- for sample code)
-
-7. Setting the size of a control raises a resize event even if the
+6. Setting the size of a control raises a resize event even if the
control size is same. Be careful is setting the size and it's better
to avoid changing the control size as much as possible. Wherever
possible try scaling the control bitmap as per the size needs.
-8. Make sure to call the base class event methods when overriding them.
-
-9. Define regions in your code, as it makes it easy to browse the code
- in the editors which can collapse/expand regions.
-
-10. To be added.
+7. Make sure to call the base class event methods when overriding them.
+
+8. Define regions in your code, as it makes it easy to browse the code
+ in the editors which can collapse/expand regions. Also, keep the
+ methods and properties sorted alphabetically.
+
+9. Last but not the least, please let others on the mono-winforms-list
+ know about your work, so that duplication can be avoided.
+
+10. Theme.cs provides Pen and Brush caching. This allows to share
+ the same brushes and pens between different controls and also to avoid
+ to create and destroy them in every draw operation. You should not create
+ Brushes or Pens directly, you should ask the Resource Pool for them. For
+ example, instead of:
+
+ new SolidBrush(button.BackColor);
+
+ you should use:
+
+ ResPool.GetSolidBrush (button.BackColor);
+
+ Look at SystemResPool class for more details.
Happy hacking!
projects / mono.git / blobdiff