customcomponents

Delphi compiler warnings pointing to Delphi's own units

In Delphi 2007, working on a project which includes a custom component, I'm getting this set of warnings as the first four in Messages when I do a full build (but not when I do a straight compile): [DCC Warning] Dialogs.pas(1426): W1002 Symbol 'TFileOpenDialog' is specific to a platform [DCC Warning] Dialogs.pas(1446): W1002 Symbol 'TFi...

How Windows (or other OSes) update client's background area?

Or to ask it another way, how OnEraseBkgnd() works? I'm building a custom control and I hit on this problem. Childs are rectangles, as usual. I had to disable OnEraseBkgnd() and I use only the OnPaint(). What I need is to efficiently clear the area behind the childs and without flickering. Techniques like using back buffers are not an o...

Frame inheritance and duplicate files in packages

I have been developing a number of components using TFrames and ModelMaker -- I've found the combination of visual design/development + inheritance + ModelMaker to be very compelling. I then register these TFrame descendants w/a registration unit, and they become full-fledges palette-based components from there. I'm using Delphi 2007. E...

Using TCollection in Delphi

I'm trying to create a custom component with a collection property. However if I try to open the collection editor during design time by clicking "..." button in object inspector, nothing happens. What I am missing? Here's my TCollection descendant: TMyCollection = class(TOwnedCollection) private function GetItem(Index: Integer...

Delphi Package: "The following changes must be made..." never goes away.

On one of my packages, which was adapted from another using Save-As and edit, I keep getting the following message (this is in Delphi 2007): ======= The following changes must be made before this package can be compiled. Choose OK to apply these changes and continue compiling. Remove cmSizePanel_Reg. Unit(s) cmSizePanel_Reg were...

How to diagnose "Cannot access package information" error in Delphi IDE

I am developing a set of TFrame-based components that inherit from one another (as so many who have helped me tremendously along the way already know!), and am running into yet another little "snag," related to packages and installation. I have essentially the following hierarchy: TFrame TBaseFRame TBaseSizeableFrame TViewerType1 ...

Why won't my Facelets loop variable go out of scope?

Hi! I know this looks like a lot of text, but I think it's a pretty simple concept I'm missing. I'm writing a web application with Facelets. I've got a custom tag rq:request-list that takes a list of requests as a parameter and outputs a lovely table to display them. So far, so good. rq:request-list starts out like you'd expect: <!--...

Delphi 2006 loses component package

Delphi 2006, whenever started afresh, loses component package. This happens on a daily bases. We have component packages with custom VCL components that we wrote ourselves. When starting up Delphi 2006, nothing is noted. But as soon as I open a form that has some of these components on it, I receive bds.exe - Unable To Locate Compone...

"Cannot load package A, it contains unit X, which is also contained in package B"

(More package/component install fun for me -- thanks everyone for all your help to date). I am getting the error listed as the title, in Delphi 2007. Package A is my package of frame-based "viewer panels." Package B is a package containing a couple of components that are used to show information about datasets linked to a gven databa...

Delphi "E2161 Error: RLINK32: Error opening file ________.drf " during Build All

I am trying to resolve a problem with a set of packages that apparently have dependency issues. Occasionally during a Build All, I get this error: Delphi "E2161 Error: RLINK32: Error opening file ____.drf " What does it mean / indicate, and what is a "drf" file? ...

Are TopCoder Components or Applications Quality Products?

Does anyone have experience with buying or using any TopCoder components or applications and do they seem like they are useful and worth the money? ...

Creating a custom form designer

I'd like to create a custom "datamodule" in Delphi, a TDataModule like (maybe inherited) class which would have a custom grid based design interface (one component per line, some properties as columns). Is this possible? Where should I start? I'm currently using Delphi 2007. ...

Delphi 2009: Pass component name onclick event then set property

I have a custom component of type TSpeedButton that has two extra properties defined: CommentHeading: string; CommentText: string; I set CommentHeading at design time. When the speed button is pressed a memo is shown with a button beneath it for saving its contents. The procedure that handles this: procedure CustomSpeedButton1Click...

Delphi 2009 - Set default property values in custom delphi components

This should be very simple but I can't find the exact answer I want. I have a custom delphi control based on TSpeedButton. I want the Caption Property of the SpeedButton to always be 'Comments' but I don't want to set it at run-time I want to set it in the component itself so that when I place it on my form it's already populated with th...

When to Install, vs. when to just build, visual component packages that are part of a larger project

Context: I have been working on and off on an application which uses a number of custom frames-based components (which folks around here have been super helpful with as I've been learning!). Since I am modifying the visual component that the app uses very often, and those components are fairly numerous and interrelated (quite a bit o...

TForm property that's an array (or collection) of TFrame descendants

I am exploring this subject again, from a slightly different angle than before: I have TForm descendant which is used in a couple of other components as a dialog, that I'd like to add as a property an array of counted TFrame descendants. What multi-item property approach should I use for this? (Array, TList, TObjectList, TCollection,...

Using TCollection with an already-defined class

(Note: This is somewhat related to my last question). I am new to using TCollection in Delphi, and am still wrapping my head around the various ways to handle one-to-many class/property-item relationships. Exploring TCollection and TCollectionItem, I ran into a couple questions: 1) Is it possible to use TCollection or TOwnedCollectio...

Android - Writing a custom (compound) component

The Android app I'm currently developing has a main activity that has grown quite large. This is mainly because it contains a TabWidget with 3 tabs. Each tab has quite a few components. The activity has to control of all those components at once. So I think you can imagine that this Activity has like 20 fields (a field for almost every c...

Visual Studio Designer: problem with custom component selection change

I have a component derived from IComponent (also tried to derive from Component) The problem: If I have 2 my custom components on the form, and one of them is selected, then I can't straightly select another my component, I have to click on something else first. Changing selection between my component and any another component (for exa...

Facelet Custom Component - prevent rendering ui:insert content in custom component

Hi, this is my custom component definition: <ui:composition xmlns="http://www.w3.org/1999/xhtml" xmlns:ui="http://java.sun.com/jsf/facelets" xmlns:h="http://java.sun.com/jsf/html" xmlns:f="http://java.sun.com/jsf/core" xmlns:c="http://java.sun.com/jstl/core" xmlns:fn="http://java.sun.com/jsp/jstl/functions"...